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source: palm/trunk/SOURCE/multi_agent_system_mod.f90 @ 3160

Last change on this file since 3160 was 3160, checked in by sward, 6 years ago
Changed C_SIZEOF to STORAGE_SIZE
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1	!> @file multi_agent_system_mod.f90
2	!--------------------------------------------------------------------------------!
3	! This file is part of PALM-4U.
4	!
5	! PALM-4U is free software: you can redistribute it and/or modify it under the
6	! terms of the GNU General Public License as published by the Free Software
7	! Foundation, either version 3 of the License, or (at your option) any later
8	! version.
9	!
10	! PALM-4U is distributed in the hope that it will be useful, but WITHOUT ANY
11	! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
12	! A PARTICULAR PURPOSE. See the GNU General Public License for more details.
13	!
14	! You should have received a copy of the GNU General Public License along with
15	! PALM. If not, see <http://www.gnu.org/licenses/>.
16	!
17	! Copyright 2016 Leibniz Universitaet Hannover
18	!------------------------------------------------------------------------------!
19	!
20	! Current revisions:
21	! ------------------
22	!
23	!
24	! Former revisions:
25	! -----------------
26	! $Id: multi_agent_system_mod.f90 3160 2018-07-20 11:52:56Z sward $
27	! Changed C_SIZEOF to STORAGE_SIZE
28	!
29	! 3159 2018-07-20 11:20:01Z sward
30	! Initial revision
31	!
32	!
33	!
34	! Authors:
35	! --------
36	! @author sward
37	!
38	!
39	! Description:
40	! ------------
41	!> Multi Agent System for the simulation of pedestrian movement in urban
42	!> environments
43	!------------------------------------------------------------------------------!
44	MODULE multi_agent_system_mod
45
46	USE, INTRINSIC :: ISO_C_BINDING
47
48	USE constants, &
49	ONLY: pi
50
51	USE control_parameters, &
52	ONLY: dt_3d, message_string, simulated_time, dt_write_agent_data
53
54	USE cpulog, &
55	ONLY: cpu_log, log_point, log_point_s
56
57	USE grid_variables, &
58	ONLY: ddx, ddy, dx, dy
59
60	USE indices, &
61	ONLY: nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, &
62	wall_flags_0
63
64	USE random_function_mod, &
65	ONLY: random_function
66
67	USE kinds
68
69	USE pegrid
70
71	CHARACTER(LEN=15) :: bc_mas_lr = 'absorb' !< left/right boundary condition
72	CHARACTER(LEN=15) :: bc_mas_ns = 'absorb' !< north/south boundary condition
73
74	INTEGER(iwp) :: deleted_agents = 0 !< number of deleted agents per time step
75	INTEGER(iwp) :: heap_count !< number of items in binary heap (for pathfinding)
76	INTEGER(iwp) :: ibc_mas_lr !< agent left/right boundary condition dummy
77	INTEGER(iwp) :: ibc_mas_ns !< agent north/south boundary condition dummy
78	INTEGER(iwp) :: ind_pm10 = -9 !< chemical species index of PM10
79	INTEGER(iwp) :: ind_pm25 = -9 !< chemical species index of PM2.5
80	INTEGER(iwp) :: iran_agent = -1234567 !< number for random generator
81	INTEGER(iwp) :: min_nr_agent = 2 !< namelist parameter (see documentation)
82	INTEGER(iwp) :: ghla_count_recv !< number of agents in left ghost layer
83	INTEGER(iwp) :: ghna_count_recv !< number of agents in north ghost layer
84	INTEGER(iwp) :: ghra_count_recv !< number of agents in right ghost layer
85	INTEGER(iwp) :: ghsa_count_recv !< number of agents in south ghost layer
86	INTEGER(iwp) :: nr_move_north !< number of agts to move north during exchange_horiz
87	INTEGER(iwp) :: nr_move_south !< number of agts to move south during exchange_horiz
88	INTEGER(iwp) :: number_of_agents = 0 !< number of agents for each grid box (3d array is saved on agt_count)
89	INTEGER(iwp) :: number_of_agent_groups = 1 !< namelist parameter (see documentation)
90	INTEGER(iwp) :: sort_count_mas = 0 !< counter for sorting agents
91	INTEGER(iwp) :: step_dealloc_mas = 100 !< namelist parameter (see documentation)
92	INTEGER(iwp) :: total_number_of_agents !< total number of agents in the whole model domain
93
94	INTEGER(iwp), PARAMETER :: NR_2_direction_move = 10000 !< parameter for agent exchange
95	INTEGER(iwp), PARAMETER :: PHASE_INIT = 1 !< phase parameter
96	INTEGER(iwp), PARAMETER :: PHASE_RELEASE = 2 !< phase parameter
97
98	INTEGER(iwp), PARAMETER :: max_number_of_agent_groups = 100 !< maximum allowed number of agent groups
99
100	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: agt_count !< 3d array of number of agents of every grid box
101	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: s_measure_height !< k-index(s-grid) for measurement
102	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: top_top_s !< k-index of first s-gridpoint above topography
103	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: top_top_w !< k-index of first v-gridpoint above topography
104	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: obstacle_flags !< flags to identify corners and edges of topography that cannot be crossed by agents
105
106	LOGICAL :: deallocate_memory_mas = .TRUE. !< namelist parameter (see documentation)
107	LOGICAL :: dt_3d_reached_mas !< flag: agent timestep has reached model timestep
108	LOGICAL :: dt_3d_reached_l_mas !< flag: agent timestep has reached model timestep
109	LOGICAL :: agents_active = .FALSE. !< flag for agent system
110	LOGICAL :: random_start_position_agents = .TRUE. !< namelist parameter (see documentation)
111	LOGICAL :: read_agents_from_restartfile = .TRUE. !< namelist parameter (see documentation)
112	LOGICAL :: agent_own_timestep = .FALSE. !< namelist parameter (see documentation)
113
114	LOGICAL, DIMENSION(max_number_of_agent_groups) :: a_rand_target = .FALSE. !< namelist parameter (see documentation)
115
116	REAL(wp) :: agent_maximum_age = 9999999.9_wp !< namelist parameter (see documentation)
117	REAL(wp) :: alloc_factor_mas = 20.0_wp !< namelist parameter (see documentation)
118	REAL(wp) :: coll_t_0 = 3. !< namelist parameter (see documentation)
119	REAL(wp) :: corner_gate_start = 0.7_wp !< namelist parameter (see documentation)
120	REAL(wp) :: corner_gate_width = 1.0_wp !< namelist parameter (see documentation)
121	REAL(wp) :: d_sigma_rep_agent !< inverse of sigma_rep_agent
122	REAL(wp) :: d_sigma_rep_wall !< inverse of sigma_rep_wall
123	REAL(wp) :: d_tau_accel_agent !< inverse of tau_accel_agent
124	REAL(wp) :: desired_speed = 1.2_wp !< namelist parameter (see documentation)
125	REAL(wp) :: des_sp_sig = .2_wp !< namelist parameter (see documentation)
126	REAL(wp) :: dist_target_reached = 2.0_wp !< distance at which target counts as reached
127	REAL(wp) :: dist_to_int_target = .75_wp !< namelist parameter (see documentation)
128	REAL(wp) :: d_sqrt_2 = 1.0_wp/SQRT(2.) !< 1/sqrt(2)
129	REAL(wp) :: dt_agent = 0.016_wp !< namelist parameter (see documentation)
130	REAL(wp) :: dt_arel = 9999999.9_wp !< namelist parameter (see documentation)
131	REAL(wp) :: end_time_arel = 9999999.9_wp !< namelist parameter (see documentation)
132	REAL(wp) :: force_x !< dummy value for force on current agent in x-direction
133	REAL(wp) :: force_y !< dummy value for force on current agent in y-direction
134	REAL(wp) :: max_dist_from_path = 1.0_wp !< distance from current path at which a new path is calculated
135	REAL(wp) :: multi_agent_system_start = 0.0_wp !< namelist parameter (see documentation)
136	REAL(wp) :: radius_agent = .2_wp !< namelist parameter (see documentation)
137	REAL(wp) :: repuls_agent = 1.5_wp !< namelist parameter (see documentation)
138	REAL(wp) :: repuls_wall = 7.0_wp !< namelist parameter (see documentation)
139	REAL(wp) :: scan_radius_agent = 3.0_wp !< namelist parameter (see documentation)
140	REAL(wp) :: scan_radius_wall = 2.0_wp !< namelist parameter (see documentation)
141	REAL(wp) :: sigma_rep_agent = 0.3_wp !< namelist parameter (see documentation)
142	REAL(wp) :: sigma_rep_wall = 0.2_wp !< namelist parameter (see documentation)
143	REAL(wp) :: tau_accel_agent = 0.5_wp !< namelist parameter (see documentation)
144	REAL(wp) :: time_arel = 0.0_wp !< time for agent release
145	REAL(wp) :: time_write_agent_data = 0.0_wp !< write agent data at current time on file
146	REAL(wp) :: v_max_agent = 1.3_wp !< namelist parameter (see documentation)
147
148
149	REAL(wp), DIMENSION(max_number_of_agent_groups) :: adx = 9999999.9_wp !< namelist parameter (see documentation)
150	REAL(wp), DIMENSION(max_number_of_agent_groups) :: ady = 9999999.9_wp !< namelist parameter (see documentation)
151	REAL(wp), DIMENSION(max_number_of_agent_groups) :: asl = 9999999.9_wp !< namelist parameter (see documentation)
152	REAL(wp), DIMENSION(max_number_of_agent_groups) :: asn = 9999999.9_wp !< namelist parameter (see documentation)
153	REAL(wp), DIMENSION(max_number_of_agent_groups) :: asr = 9999999.9_wp !< namelist parameter (see documentation)
154	REAL(wp), DIMENSION(max_number_of_agent_groups) :: ass = 9999999.9_wp !< namelist parameter (see documentation)
155	REAL(wp), DIMENSION(max_number_of_agent_groups) :: at_x = 9999999.9_wp !< namelist parameter (see documentation)
156	REAL(wp), DIMENSION(max_number_of_agent_groups) :: at_y = 9999999.9_wp !< namelist parameter (see documentation)
157	!
158	!-- Type for the definition of an agent
159	TYPE agent_type
160	INTEGER(iwp) :: block_nr !< number for sorting
161	INTEGER(iwp) :: group !< number of agent group
162	INTEGER(idp) :: id !< particle ID (64 bit integer)
163	INTEGER(iwp) :: path_counter !< current target along path (path_x/y)
164	LOGICAL :: agent_mask !< if this parameter is set to false the agent will be deleted
165	REAL(wp) :: age !< age of agent
166	REAL(wp) :: age_m !< age of agent
167	REAL(wp) :: dt_sum !< sum of agents subtimesteps
168	REAL(wp) :: clo !< clothing index
169	REAL(wp) :: energy_storage !< energy stored by agent
170	REAL(wp) :: force_x !< force term x-direction
171	REAL(wp) :: force_y !< force term y-direction
172	REAL(wp) :: origin_x !< origin x-position of agent
173	REAL(wp) :: origin_y !< origin y-position of agent
174	REAL(wp) :: pm10 !< PM10 concentration at agent position
175	REAL(wp) :: pm25 !< PM25 concentration at agent position
176	REAL(wp) :: speed_abs !< absolute value of agent speed
177	REAL(wp) :: speed_e_x !< normalized speed of agent in x
178	REAL(wp) :: speed_e_y !< normalized speed of agent in y
179	REAL(wp) :: speed_des !< agent's desired speed
180	REAL(wp) :: speed_x !< speed of agent in x
181	REAL(wp) :: speed_y !< speed of agent in y
182	REAL(wp) :: thermal_index !< the dynamic thermal index
183	REAL(wp) :: windspeed !< absolute value of windspeed at agent position
184	REAL(wp) :: x !< x-position
185	REAL(wp) :: y !< y-position
186	REAL(wp) :: t !< temperature
187	REAL(wp) :: t_x !< x-position
188	REAL(wp) :: t_y !< y-position
189	REAL(wp), DIMENSION(0:15) :: path_x !< agent path to target (x)
190	REAL(wp), DIMENSION(0:15) :: path_y !< agent path to target (y)
191	END TYPE agent_type
192
193	TYPE(agent_type), DIMENSION(:), POINTER :: agents !< Agent array for this grid cell
194	TYPE(agent_type) :: zero_agent !< zero agent to avoid weird thing
195	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: move_also_north !< for agent exchange between PEs
196	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: move_also_south !< for agent exchange between PEs
197	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: agt_gh_l !< ghost layer left of pe domain
198	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: agt_gh_n !< ghost layer north of pe domain
199	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: agt_gh_r !< ghost layer right of pe domain
200	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: agt_gh_s !< ghost layer south of pe domain
201	!
202	!-- Type for 2D grid on which agents are stored
203	TYPE grid_agent_def
204	INTEGER(iwp), DIMENSION(0:3) :: start_index !< start agent index for current block
205	INTEGER(iwp), DIMENSION(0:3) :: end_index !< end agent index for current block
206	INTEGER(iwp) :: id_counter !< agent id counter (removeable?)
207	LOGICAL :: time_loop_done !< timestep loop for agent advection
208	TYPE(agent_type), POINTER, DIMENSION(:) :: agents !< Particle array for this grid cell
209	END TYPE grid_agent_def
210
211	TYPE(grid_agent_def), DIMENSION(:,:), ALLOCATABLE, TARGET :: grid_agents !< 2D grid on which agents are stored
212	!
213	!-- Item in a priority queue (binary heap)
214	TYPE heap_item
215	INTEGER(iwp) :: mesh_id !< id of the submitted mesh point
216	REAL(wp) :: priority !< priority of the mesh point (= distance so far + heuristic to goal)
217	END TYPE heap_item
218
219	TYPE(heap_item), DIMENSION(:), ALLOCATABLE :: queue !< priority queue realized as binary heap
220	!
221	!-- Type for mesh point in visibility graph
222	TYPE mesh_point
223	INTEGER(iwp) :: polygon_id !< Polygon the point belongs to
224	INTEGER(iwp) :: vertex_id !< Vertex in the polygon
225	INTEGER(iwp) :: noc !< number of connections
226	INTEGER(iwp) :: origin_id !< ID of previous mesh point on path (A*)
227	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: connected_vertices !< Index of connected vertices
228	REAL(wp) :: cost_so_far !< Cost to reach this mesh point (A*)
229	REAL(wp) :: x !< x-coordinate
230	REAL(wp) :: y !< y-coordinate
231	REAL(wp) :: x_s !< corner shifted outward from building by 1m (x)
232	REAL(wp) :: y_s !< corner shifted outward from building by 1m (y)
233	REAL(wp), DIMENSION(:), ALLOCATABLE :: distance_to_vertex !< Distance to each vertex
234	END TYPE mesh_point
235
236	TYPE(mesh_point), DIMENSION(:), ALLOCATABLE :: mesh !< navigation mesh
237	TYPE(mesh_point), DIMENSION(:), ALLOCATABLE :: tmp_mesh !< temporary navigation mesh
238	!
239	!-- Vertex of a polygon
240	TYPE vertex_type
241	LOGICAL :: delete !< Flag to mark vertex for deletion
242	REAL(wp) :: x !< x-coordinate
243	REAL(wp) :: y !< y-coordinate
244	END TYPE vertex_type
245	!
246	!-- Polygon containing a number of vertices
247	TYPE polygon_type
248	INTEGER(iwp) :: nov !< Number of vertices in this polygon
249	TYPE(vertex_type), DIMENSION(:), ALLOCATABLE :: vertices !< Array of vertices
250	END TYPE polygon_type
251
252	TYPE(polygon_type), DIMENSION(:), ALLOCATABLE :: polygons !< Building data in polygon form
253
254	SAVE
255
256	PRIVATE
257	!
258	!-- Public functions
259	PUBLIC mas_init, mas_parin, multi_agent_system
260
261	!
262	!-- Public parameters, constants and initial values
263	PUBLIC agents_active, multi_agent_system_start
264
265	INTERFACE mas_parin
266	MODULE PROCEDURE mas_parin
267	END INTERFACE mas_parin
268
269	INTERFACE mas_init
270	MODULE PROCEDURE mas_init
271	END INTERFACE mas_init
272
273	INTERFACE multi_agent_system
274	MODULE PROCEDURE multi_agent_system
275	END INTERFACE multi_agent_system
276
277	CONTAINS
278
279
280	!------------------------------------------------------------------------------!
281	! Description:
282	! ------------
283	!> Multi Agent System:
284	!> executes a number of agents sub-timesteps until the model timestep is reached.
285	!> The agent timestep is usually smaller than the model timestep
286	!------------------------------------------------------------------------------!
287	SUBROUTINE multi_agent_system
288
289	! USE htcm_mod, &
290	! ONLY: htcm_dynamic
291
292	IMPLICIT NONE
293
294	INTEGER(iwp) :: i !< counter
295	INTEGER(iwp) :: ie !< counter
296	INTEGER(iwp) :: is !< counter
297	INTEGER(iwp) :: j !< counter
298	INTEGER(iwp) :: je !< counter
299	INTEGER(iwp) :: js !< counter
300	INTEGER(iwp), SAVE :: mas_count = 0 !< counts the mas-calls
301
302	LOGICAL :: first_loop_stride !< flag for first loop stride of agent sub-timesteps
303	LOGICAL :: first_call = .TRUE. !< first call of mas flag for output
304
305	CALL cpu_log( log_point(9), 'mas', 'start' )
306	!
307	!-- Initialize variables for the next (sub-) timestep, i.e., for marking
308	!-- those agents to be deleted after the timestep
309	deleted_agents = 0
310	!
311	!-- If necessary, release new set of agents
312	IF ( time_arel >= dt_arel .AND. end_time_arel > simulated_time ) THEN
313
314	CALL mas_create_agent(PHASE_RELEASE)
315	!
316	!-- The MOD function allows for changes in the output interval with
317	!-- restart runs.
318	time_arel = MOD( time_arel, MAX( dt_arel, dt_3d ) )
319
320	ENDIF
321
322	first_loop_stride = .TRUE.
323	grid_agents(:,:)%time_loop_done = .TRUE.
324	!
325	!-- Set timestep variable
326	IF ( .NOT. agent_own_timestep ) dt_agent = dt_3d
327	!
328	!-- Timestep loop for agent transport.
329	!-- This loop has to be repeated until the transport time of every agent
330	!-- (within the total domain!) has reached the LES timestep (dt_3d).
331	!-- Timestep scheme is Euler-forward
332	DO
333	!
334	!-- Write agent data at current time on file.
335	time_write_agent_data = time_write_agent_data + dt_agent
336	IF ( time_write_agent_data >= dt_write_agent_data ) THEN
337	#if defined( __netcdf )
338	IF ( first_loop_stride ) CALL mas_get_prognostic_quantities
339	CALL mas_data_output_agents ( first_call )
340	#else
341	WRITE( message_string, * ) 'NetCDF is needed for agent output. ', &
342	'Set __netcdf in compiler options'
343	CALL message( 'multi_agent_system', 'PA0071', 1, 2, 0, 6, 0 )
344	#endif
345	IF(first_call) first_call = .FALSE.
346	time_write_agent_data = time_write_agent_data - dt_write_agent_data
347	ENDIF
348	!
349	!-- Start logging
350	CALL cpu_log( log_point_s(9), 'mas_transport', 'start' )
351	CALL cpu_log( log_point_s(9), 'mas_transport', 'pause' )
352	CALL cpu_log( log_point_s(16), 'mas_other_agents', 'start' )
353	CALL cpu_log( log_point_s(16), 'mas_other_agents', 'pause' )
354	!
355	!-- Flag is true by default, will be set to false if an agent has not yet
356	!-- reached the model timestep
357	grid_agents(:,:)%time_loop_done = .TRUE.
358
359	!
360	!-- First part of agent transport:
361	!-- Evaluate social forces for all agents at current positions
362	DO i = nxl, nxr
363	DO j = nys, nyn
364
365	number_of_agents = agt_count(j,i)
366	!
367	!-- If grid cell is empty, cycle
368	IF ( number_of_agents <= 0 ) CYCLE
369
370	agents => grid_agents(j,i)%agents(1:number_of_agents)
371	!
372	!-- Evaluation of social forces
373	CALL mas_timestep_forces_call(i,j)
374
375	ENDDO
376	ENDDO
377	!
378	!-- Second part of agent transport:
379	!-- timestep
380	DO i = nxl, nxr
381	DO j = nys, nyn
382
383	number_of_agents = agt_count(j,i)
384	!
385	!-- If grid cell is empty, flag must be true
386	IF ( number_of_agents <= 0 ) THEN
387	grid_agents(j,i)%time_loop_done = .TRUE.
388	CYCLE
389	ENDIF
390
391	agents => grid_agents(j,i)%agents(1:number_of_agents)
392
393	agents(1:number_of_agents)%agent_mask = .TRUE.
394	!
395	!-- Initialize the variable storing the total time that an agent
396	!-- has advanced within the timestep procedure
397	IF ( first_loop_stride ) THEN
398	agents(1:number_of_agents)%dt_sum = 0.0_wp
399	ENDIF
400	!
401	!-- Initialize the switch used for the loop exit condition checked
402	!-- at the end of this loop. If at least one agent has failed to
403	!-- reach the LES timestep, this switch will be set false in
404	!-- mas_transport.
405	dt_3d_reached_l_mas = .TRUE.
406	!
407	!-- Timestep
408	CALL mas_timestep
409	!
410	!-- Delete agents that have been simulated longer than allowed
411	CALL mas_boundary_conds( 'max_sim_time' )
412	!
413	!-- Delete agents that have reached target area
414	CALL mas_boundary_conds( 'target_area' )
415	!
416	!--- If not all agents of the actual grid cell have reached the
417	!-- LES timestep, this cell has to to another loop iteration. Due to
418	!-- the fact that agents can move into neighboring grid cell,
419	!-- these neighbor cells also have to perform another loop iteration
420	IF ( .NOT. dt_3d_reached_l_mas ) THEN
421	js = MAX(nys,j-1)
422	je = MIN(nyn,j+1)
423	is = MAX(nxl,i-1)
424	ie = MIN(nxr,i+1)
425	grid_agents(js:je,is:ie)%time_loop_done = .FALSE.
426	ENDIF
427
428	ENDDO
429	ENDDO
430
431	!
432	!-- Find out, if all agents on every PE have completed the LES timestep
433	!-- and set the switch corespondingly
434	dt_3d_reached_l_mas = ALL(grid_agents(:,:)%time_loop_done)
435	#if defined( __parallel )
436	IF ( collective_wait ) CALL MPI_BARRIER( comm2d, ierr )
437	CALL MPI_ALLREDUCE( dt_3d_reached_l_mas, dt_3d_reached_mas, 1, MPI_LOGICAL, &
438	MPI_LAND, comm2d, ierr )
439	#else
440	dt_3d_reached_mas = dt_3d_reached_l_mas
441	#endif
442
443	CALL cpu_log( log_point_s(9), 'mas_transport', 'stop' )
444	CALL cpu_log( log_point_s(16), 'mas_other_agents', 'stop' )
445	!
446	!-- Increment time since last release
447	IF ( dt_3d_reached_mas ) time_arel = time_arel + dt_3d
448
449	!
450	!-- Move Agents local to PE to a different grid cell
451	CALL mas_eh_move_agent
452	!
453	!-- Horizontal boundary conditions including exchange between subdmains
454	CALL mas_eh_exchange_horiz
455	!
456	!-- Pack agents (eliminate those marked for deletion),
457	!-- determine new number of agents
458	CALL mas_ps_sort_in_subboxes
459	!
460	!-- Initialize variables for the next (sub-) timestep, i.e., for marking
461	!-- those agents to be deleted after the timestep
462	deleted_agents = 0
463	!
464	!-- to be included here: call of human thermal comfort mod (and UV exposure)
465	! DO i = nxl, nxr
466	! DO j = nys, nyn
467	!
468	! number_of_agents = agt_count(j,i)
469	! !
470	! !-- If grid cell gets empty, cycle
471	! IF ( number_of_agents <= 0 ) CYCLE
472	!
473	! agents => grid_agents(j,i)%agents(1:number_of_agents)
474	! !
475	! !-- Evaluation of social forces
476	! CALL htcm_dynamic(i,j)
477	!
478	! ENDDO
479	! ENDDO
480
481	IF ( dt_3d_reached_mas ) EXIT
482
483	first_loop_stride = .FALSE.
484	ENDDO ! timestep loop
485
486	!
487	!-- Deallocate unused memory
488	IF ( deallocate_memory_mas .AND. mas_count == step_dealloc_mas ) THEN
489	CALL mas_eh_dealloc_agents_array
490	mas_count = 0
491	ELSEIF ( deallocate_memory_mas ) THEN
492	mas_count = mas_count + 1
493	ENDIF
494
495	CALL cpu_log( log_point(9), 'mas', 'stop' )
496
497	END SUBROUTINE multi_agent_system
498
499	!------------------------------------------------------------------------------!
500	! Description:
501	! ------------
502	!> Calculation of the direction vector from each agent to its current
503	!> intermittent target
504	!------------------------------------------------------------------------------!
505	SUBROUTINE mas_agent_direction
506
507	IMPLICIT NONE
508
509	LOGICAL :: path_flag !< true if new path must be calculated
510
511	INTEGER(iwp) :: n !< loop variable over all agents in a grid box
512	INTEGER(iwp) :: pc !< agent path counter
513
514	REAL(wp) :: abs_dir !< length of direction vector (for normalization)
515	REAL(wp) :: d_curr_target !< rounding influence expressed as x speed component
516	REAL(wp) :: d_prev_target !< rounding influence expressed as x speed component
517	REAL(wp) :: dir_x !< direction of agent (x)
518	REAL(wp) :: dir_y !< direction of agent (y)
519	REAL(wp) :: dist_round = 3. !< distance at which agents start rounding a corner
520	REAL(wp) :: dtit !< distance to intermittent target
521	REAL(wp) :: round_fac = .2 !< factor for rounding influence
522	REAL(wp) :: speed_round_x !< rounding influence expressed as x speed component
523	REAL(wp) :: speed_round_y !< rounding influence expressed as x speed component
524
525	CALL cpu_log( log_point_s(9), 'mas_transport', 'continue' )
526	!
527	!-- loop over all agents in the current grid box
528	DO n = 1, number_of_agents
529	path_flag = .FALSE.
530	pc = agents(n)%path_counter
531	!
532	!-- If no path was calculated for agent yet, do it
533	IF ( pc >= 999 ) THEN
534
535	agents(n)%path_x(0) = agents(n)%origin_x
536	agents(n)%path_y(0) = agents(n)%origin_y
537	CALL mas_nav_find_path(n)
538	pc = agents(n)%path_counter
539	!
540	!-- Check if new path must be calculated and if so, do it
541	ELSE
542	!
543	!-- Case one: Agent has come close enough to intermittent target.
544	!-- -> chose new int target and calculate rest of path if no
545	!-- new intermittent targets are left
546	dtit = SQRT((agents(n)%x - agents(n)%path_x(pc))**2 &
547	+ (agents(n)%y - agents(n)%path_y(pc))**2)
548	IF ( dtit < dist_to_int_target ) THEN
549	agents(n)%path_counter = agents(n)%path_counter + 1
550	pc = agents(n)%path_counter
551	!
552	!-- Path counter out of scope (each agent can store a maximum of 15
553	!-- intermittent targets on the way to her final target); new path
554	!-- must be calculated
555	IF ( pc >= SIZE(agents(n)%path_x) ) THEN
556	path_flag = .TRUE.
557	ENDIF
558	!
559	!-- Case two: Agent too far from path
560	!-- -> set flag for new path to be calculated
561	ELSEIF ( dist_point_to_edge(agents(n)%path_x(pc-1), &
562	agents(n)%path_y(pc-1), &
563	agents(n)%path_x(pc), &
564	agents(n)%path_y(pc), &
565	agents(n)%x, agents(n)%y) &
566	> max_dist_from_path ) &
567	THEN
568	path_flag = .TRUE.
569	ENDIF
570	!
571	!-- If either of the above two cases was true, calculate new path and
572	!-- reset 0th path point. This point (the last target the agent had)
573	!-- is needed for the agents rounding of corners and the calculation
574	!-- of her deviation from her current path
575	IF ( path_flag ) THEN
576	agents(n)%path_x(0) = agents(n)%path_x(pc-1)
577	agents(n)%path_y(0) = agents(n)%path_y(pc-1)
578	CALL mas_nav_find_path(n)
579	pc = agents(n)%path_counter
580	ENDIF
581	ENDIF
582	!
583	!-- Normalize direction vector
584	abs_dir = 1.0d-12
585	dir_x = agents(n)%path_x(pc) - agents(n)%x
586	dir_y = agents(n)%path_y(pc) - agents(n)%y
587	abs_dir = SQRT(dir_x2 + dir_y2)+1.0d-12
588	!-- needed later for corner rounding
589	! dir_x = dir_x/abs_dir
590	! dir_y = dir_y/abs_dir
591	! dir_x = dir_x + speed_round_x
592	! dir_y = dir_y + speed_round_y
593	! abs_dir = SQRT(dir_x2 + dir_y2)+1.0d-12
594	agents(n)%speed_e_x = dir_x/abs_dir
595	agents(n)%speed_e_y = dir_y/abs_dir
596	ENDDO
597
598	CALL cpu_log( log_point_s(9), 'mas_transport', 'pause' )
599	!
600	!-- corner rounding; to be added
601	!
602	!-- Calculate direction change due to rounding of corners
603
604	! speed_round_x = 0.
605	! speed_round_y = 0.
606	!
607	! d_curr_target = SQRT( (agents(n)%path_x(pc) - agents(n)%x)**2 + &
608	! (agents(n)%path_y(pc) - agents(n)%y)**2 )
609	! d_prev_target = SQRT( (agents(n)%path_x(pc-1) - agents(n)%x)**2 + &
610	! (agents(n)%path_y(pc-1) - agents(n)%y)**2 )
611	! !
612	! !-- Agent is close to next target and that target is not the final one
613	! IF ( d_curr_target < dist_round .AND. dist_round < &
614	! SQRT( (agents(n)%path_x(pc) - agents(n)%t_x)**2 + &
615	! (agents(n)%path_y(pc) - agents(n)%t_y)**2 ) ) &
616	! THEN
617	! speed_round_x = (agents(n)%path_x(pc+1) - agents(n)%path_x(pc)) / &
618	! ABS( agents(n)%path_x(pc) &
619	! - agents(n)%path_x(pc+1)) * round_fac * &
620	! SIN( pi/dist_round*d_curr_target )
621	! speed_round_y = (agents(n)%path_y(pc+1) - agents(n)%path_y(pc)) / &
622	! ABS( agents(n)%path_y(pc) &
623	! - agents(n)%path_y(pc+1)) * round_fac * &
624	! SIN( pi/dist_round*d_curr_target )
625	! ENDIF
626	!
627	! IF ( d_prev_target < dist_round ) THEN
628	! IF ( agents(n)%path_x(pc) /= agents(n)%path_x(pc+1) ) THEN
629	! speed_round_x = speed_round_x + &
630	! (agents(n)%path_x(pc) - agents(n)%path_x(pc+1)) / &
631	! ABS( agents(n)%path_x(pc) &
632	! - agents(n)%path_x(pc+1)) * round_fac * &
633	! SIN( pi/dist_round*d_prev_target )
634	! ENDIF
635	!
636	! IF ( agents(n)%path_y(pc) /= agents(n)%path_y(pc+1) ) THEN
637	! speed_round_y = speed_round_y + &
638	! (agents(n)%path_y(pc) - agents(n)%path_y(pc+1)) / &
639	! ABS( agents(n)%path_y(pc) &
640	! - agents(n)%path_y(pc+1)) * round_fac * &
641	! SIN( pi/dist_round*d_prev_target )
642	! ENDIF
643
644	! ENDIF
645
646
647	END SUBROUTINE mas_agent_direction
648
649	!------------------------------------------------------------------------------!
650	! Description:
651	! ------------
652	!> Boundary conditions for maximum time, target reached and out of domain
653	!------------------------------------------------------------------------------!
654	SUBROUTINE mas_boundary_conds( location )
655
656	IMPLICIT NONE
657
658	CHARACTER (LEN=*) :: location !< Identifier
659
660	INTEGER(iwp) :: n !< agent number
661	INTEGER(iwp) :: grp !< agent group
662
663	REAL(wp) :: dist_to_target !< distance to target
664
665	IF ( location == 'max_sim_time' ) THEN
666
667	!
668	!-- Delete agents that have been simulated longer than allowed
669	DO n = 1, number_of_agents
670
671	IF ( agents(n)%age > agent_maximum_age .AND. &
672	agents(n)%agent_mask ) &
673	THEN
674	agents(n)%agent_mask = .FALSE.
675	deleted_agents = deleted_agents + 1
676	ENDIF
677
678	ENDDO
679	ENDIF
680
681	IF ( location == 'target_area' ) THEN
682
683	!
684	!-- Delete agents that entered target region
685	DO n = 1, number_of_agents
686	grp = agents(n)%group
687	dist_to_target = SQRT((agents(n)%x-at_x(grp))**2 &
688	+ (agents(n)%y-at_y(grp))**2)
689	IF ( dist_to_target < dist_target_reached ) THEN
690	agents(n)%agent_mask = .FALSE.
691	deleted_agents = deleted_agents + 1
692	ENDIF
693
694	ENDDO
695	ENDIF
696
697	END SUBROUTINE mas_boundary_conds
698
699	!------------------------------------------------------------------------------!
700	! Description:
701	! ------------
702	!> Release new agents at their respective sources
703	!------------------------------------------------------------------------------!
704	SUBROUTINE mas_create_agent (phase)
705
706	IMPLICIT NONE
707
708	INTEGER(iwp) :: alloc_size !< relative increase of allocated memory for agents
709	INTEGER(iwp) :: i !< loop variable ( agent groups )
710	INTEGER(iwp) :: ip !< index variable along x
711	INTEGER(iwp) :: j !< loop variable ( agents per point )
712	INTEGER(iwp) :: jp !< index variable along y
713	INTEGER(iwp) :: loop_stride !< loop variable for initialization
714	INTEGER(iwp) :: n !< loop variable ( number of agents )
715	INTEGER(iwp) :: new_size !< new size of allocated memory for agents
716	INTEGER(iwp) :: rn_side !< index of agent path
717
718	INTEGER(iwp), INTENT(IN) :: phase !< mode of inititialization
719
720	INTEGER(iwp), DIMENSION(nysg:nyng,nxlg:nxrg) :: local_count !< start address of new agent
721	INTEGER(iwp), DIMENSION(nysg:nyng,nxlg:nxrg) :: local_start !< start address of new agent
722
723	LOGICAL :: first_stride !< flag for initialization
724
725	REAL(wp) :: pos_x !< increment for agent position in x
726	REAL(wp) :: pos_y !< increment for agent position in y
727	REAL(wp) :: rand_contr !< dummy argument for random position
728	REAL(wp) :: rn_side_dum !< index of agent path
729
730	TYPE(agent_type),TARGET :: tmp_agent !< temporary agent used for initialization
731
732	!
733	!-- Calculate agent positions and store agent attributes, if
734	!-- agent is situated on this PE
735	DO loop_stride = 1, 2
736	first_stride = (loop_stride == 1)
737	IF ( first_stride ) THEN
738	local_count = 0 ! count number of agents
739	ELSE
740	local_count = agt_count ! Start address of new agents
741	ENDIF
742
743	DO i = 1, number_of_agent_groups
744
745	pos_y = ass(i)
746
747	DO WHILE ( pos_y <= asn(i) )
748
749	IF ( pos_y >= nys * dy .AND. &
750	pos_y < ( nyn + 1 ) * dy ) &
751	THEN
752
753	pos_x = asl(i)
754
755	xloop: DO WHILE ( pos_x <= asr(i) )
756
757	IF ( pos_x >= nxl * dx .AND. &
758	pos_x < ( nxr + 1) * dx ) &
759	THEN
760
761	tmp_agent%agent_mask = .TRUE.
762	tmp_agent%group = i
763	tmp_agent%id = 0_idp
764	tmp_agent%block_nr = -1
765	tmp_agent%path_counter = 999 !SIZE(tmp_agent%path_x)
766	tmp_agent%age = 0.0_wp
767	tmp_agent%age_m = 0.0_wp
768	tmp_agent%dt_sum = 0.0_wp
769	tmp_agent%clo = 99999.0_wp
770	tmp_agent%energy_storage= 0.0_wp
771	tmp_agent%force_x = 0.0_wp
772	tmp_agent%force_y = 0.0_wp
773	tmp_agent%origin_x = pos_x
774	tmp_agent%origin_y = pos_y
775	tmp_agent%speed_abs = 0.0_wp
776	tmp_agent%speed_e_x = 0.0_wp
777	tmp_agent%speed_e_y = 0.0_wp
778	tmp_agent%speed_des = random_normal(desired_speed,&
779	des_sp_sig)
780	tmp_agent%speed_x = 0.0_wp
781	tmp_agent%speed_y = 0.0_wp
782	tmp_agent%thermal_index = 99999.0_wp
783	tmp_agent%x = pos_x
784	tmp_agent%y = pos_y
785	tmp_agent%path_x = -1.0_wp
786	tmp_agent%path_y = -1.0_wp
787	tmp_agent%t_x = - pi
788	tmp_agent%t_y = - pi
789	!
790	!-- Determine the grid indices of the agent position
791	ip = tmp_agent%x * ddx
792	jp = tmp_agent%y * ddy
793	!
794	!-- Give each agent its target
795	IF ( a_rand_target(i) ) THEN
796	!
797	!-- Agent shall receive random target just outside
798	!-- simulated area
799	rn_side_dum = random_function(iran_agent)
800	rn_side = FLOOR(4.*rn_side_dum)
801	IF ( rn_side < 2 ) THEN
802	IF ( rn_side == 0 ) THEN
803	tmp_agent%t_y = -2*dy
804	ELSE
805	tmp_agent%t_y = (ny+3)*dy
806	ENDIF
807	tmp_agent%t_x = random_function(iran_agent) * &
808	(nx+1)*dx
809	ELSE
810	IF ( rn_side == 2 ) THEN
811	tmp_agent%t_x = -2*dx
812	ELSE
813	tmp_agent%t_x = (nx+3)*dx
814	ENDIF
815	tmp_agent%t_y = random_function(iran_agent) * &
816	(ny+1)*dy
817	ENDIF
818	!
819	!-- Agent gets target of her group
820	ELSE
821	tmp_agent%t_x = at_x(i)
822	tmp_agent%t_y = at_y(i)
823	ENDIF
824
825	local_count(jp,ip) = local_count(jp,ip) + 1
826
827	IF ( .NOT. first_stride ) THEN
828	grid_agents(jp,ip)%agents(local_count(jp,ip)) &
829	= tmp_agent
830	ENDIF
831
832	ENDIF
833
834	pos_x = pos_x + adx(i)
835
836	ENDDO xloop
837
838	ENDIF
839
840	pos_y = pos_y + ady(i)
841
842	ENDDO
843
844	ENDDO
845
846	!
847	!-- Allocate or reallocate agents array to new size
848	IF ( first_stride ) THEN
849	DO ip = nxlg, nxrg
850	DO jp = nysg, nyng
851	IF ( phase == PHASE_INIT ) THEN
852	IF ( local_count(jp,ip) > 0 ) THEN
853	alloc_size = MAX( INT( local_count(jp,ip) * &
854	( 1.0_wp + alloc_factor_mas / 100.0_wp ) ), &
855	min_nr_agent )
856	ELSE
857	alloc_size = min_nr_agent
858	ENDIF
859	ALLOCATE(grid_agents(jp,ip)%agents(1:alloc_size))
860	DO n = 1, alloc_size
861	grid_agents(jp,ip)%agents(n) = zero_agent
862	ENDDO
863	ELSEIF ( phase == PHASE_RELEASE ) THEN
864	IF ( local_count(jp,ip) > 0 ) THEN
865	new_size = local_count(jp,ip) + agt_count(jp,ip)
866	alloc_size = MAX( INT( new_size * ( 1.0_wp + &
867	alloc_factor_mas / 100.0_wp ) ), min_nr_agent )
868	IF( alloc_size > SIZE( grid_agents(jp,ip)%agents) ) &
869	THEN
870	CALL mas_eh_realloc_agents_array(ip,jp,alloc_size)
871	ENDIF
872	ENDIF
873	ENDIF
874	ENDDO
875	ENDDO
876	ENDIF
877
878	ENDDO
879
880	local_start = agt_count+1
881	agt_count = local_count
882
883	!
884	!-- Calculate agent IDs
885	DO ip = nxl, nxr
886	DO jp = nys, nyn
887	number_of_agents = agt_count(jp,ip)
888	IF ( number_of_agents <= 0 ) CYCLE
889	agents => grid_agents(jp,ip)%agents(1:number_of_agents)
890
891	DO n = local_start(jp,ip), number_of_agents !only new agents
892
893	agents(n)%id = 10000_idp*2 grid_agents(jp,ip)%id_counter + &
894	10000_idp * jp + ip
895	!
896	!-- Count the number of agents that have been released before
897	grid_agents(jp,ip)%id_counter = grid_agents(jp,ip)%id_counter &
898	+ 1
899
900	ENDDO
901
902	ENDDO
903	ENDDO
904
905	!
906	!-- Add random fluctuation to agent positions.
907	IF ( random_start_position_agents ) THEN
908	DO ip = nxl, nxr
909	DO jp = nys, nyn
910	number_of_agents = agt_count(jp,ip)
911	IF ( number_of_agents <= 0 ) CYCLE
912	agents => grid_agents(jp,ip)%agents(1:number_of_agents)
913	!
914	!-- Move only new agents. Moreover, limit random fluctuation
915	!-- in order to prevent that agents move more than one grid box,
916	!-- which would lead to problems concerning agent exchange
917	!-- between processors in case adx/ady are larger than dx/dy,
918	!-- respectively.
919	DO n = local_start(jp,ip), number_of_agents
920	IF ( asl(agents(n)%group) /= asr(agents(n)%group) ) THEN
921	rand_contr = ( random_function( iran_agent ) - 0.5_wp ) *&
922	adx(agents(n)%group)
923	agents(n)%x = agents(n)%x + &
924	MERGE( rand_contr, SIGN( dx, rand_contr ), &
925	ABS( rand_contr ) < dx &
926	)
927	ENDIF
928	IF ( ass(agents(n)%group) /= asn(agents(n)%group) ) THEN
929	rand_contr = ( random_function( iran_agent ) - 0.5_wp ) *&
930	ady(agents(n)%group)
931	agents(n)%y = agents(n)%y + &
932	MERGE( rand_contr, SIGN( dy, rand_contr ), &
933	ABS( rand_contr ) < dy )
934	ENDIF
935	ENDDO
936	!
937	!-- Delete agents that have been simulated longer than allowed
938	CALL mas_boundary_conds( 'max_sim_time' )
939	!
940	!-- Delete agents that have reached target area
941	CALL mas_boundary_conds( 'target_area' )
942
943	ENDDO
944	ENDDO
945	!
946	!-- Exchange agents between grid cells and processors
947	CALL mas_eh_move_agent
948	CALL mas_eh_exchange_horiz
949
950	ENDIF
951	!
952	!-- In case of random_start_position_agents, delete agents identified by
953	!-- mas_eh_exchange_horiz and mas_boundary_conds. Then sort agents into
954	!-- blocks, which is needed for a fast interpolation of the LES fields
955	!-- on the agent position.
956	CALL mas_ps_sort_in_subboxes
957
958	!
959	!-- Determine the current number of agents
960	number_of_agents = 0
961	DO ip = nxl, nxr
962	DO jp = nys, nyn
963	number_of_agents = number_of_agents + agt_count(jp,ip)
964	ENDDO
965	ENDDO
966	!
967	!-- Calculate the number of agents of the total domain
968	#if defined( __parallel )
969	IF ( collective_wait ) CALL MPI_BARRIER( comm2d, ierr )
970	CALL MPI_ALLREDUCE( number_of_agents, total_number_of_agents, 1, &
971	MPI_INTEGER, MPI_SUM, comm2d, ierr )
972	#else
973	total_number_of_agents = number_of_agents
974	#endif
975
976	RETURN
977
978	END SUBROUTINE mas_create_agent
979
980	!------------------------------------------------------------------------------!
981	! Description:
982	! ------------
983	!> Creates flags that indicate if a gridbox contains edges or corners. These
984	!> flags are used for agents to check if obstacles are close to them.
985	!------------------------------------------------------------------------------!
986	SUBROUTINE mas_create_obstacle_flags
987
988	USE arrays_3d, &
989	ONLY: zw
990
991	IMPLICIT NONE
992
993	INTEGER(iwp) :: agt_size !< Agent size in bytes
994	INTEGER(iwp) :: dummy !< dummy
995	INTEGER(iwp) :: il
996	INTEGER(iwp) :: jl
997
998	ALLOCATE(obstacle_flags(nysg:nyng,nxlg:nxrg))
999
1000	obstacle_flags = 0
1001
1002	DO il = nxlg, nxrg
1003	DO jl = nysg, nyng
1004	!
1005	!-- North edge
1006	IF ( jl < nyng ) THEN
1007	IF ( ( top_top_s(jl,il) - top_top_s(jl+1,il) ) > 1 .AND. &
1008	( zw( top_top_w(jl,il) ) - &
1009	zw( top_top_w(jl+1,il) ) ) > .51_wp ) &
1010	THEN
1011	obstacle_flags(jl,il) = IBSET( obstacle_flags(jl,il), 0 )
1012	ENDIF
1013	ENDIF
1014	!
1015	!-- North right corner
1016	IF ( jl < nyng .AND. il < nxrg ) THEN
1017	IF ( ( top_top_s(jl,il) - top_top_s(jl+1,il) ) > 1 .AND. &
1018	( top_top_s(jl,il) - top_top_s(jl+1,il+1) ) > 1 .AND. &
1019	( top_top_s(jl,il) - top_top_s(jl,il+1) ) > 1 .AND. &
1020	( zw( top_top_w(jl,il) ) - &
1021	zw( top_top_w(jl+1,il+1) ) ) > .51_wp ) &
1022	THEN
1023	obstacle_flags(jl,il) = IBSET( obstacle_flags(jl,il), 1 )
1024	ENDIF
1025	ENDIF
1026	!
1027	!-- Right edge
1028	IF ( il < nxrg ) THEN
1029	IF ( ( top_top_s(jl,il) - top_top_s(jl,il+1) ) > 1 .AND. &
1030	( zw( top_top_w(jl,il) ) - &
1031	zw( top_top_w(jl,il+1) ) ) > .51_wp ) &
1032	THEN
1033	obstacle_flags(jl,il) = IBSET( obstacle_flags(jl,il), 2 )
1034	ENDIF
1035	ENDIF
1036	!
1037	!-- South right corner
1038	IF ( jl > nysg .AND. il < nxrg ) THEN
1039	IF ( ( top_top_s(jl,il) - top_top_s(jl,il+1) ) > 1 .AND. &
1040	( top_top_s(jl,il) - top_top_s(jl-1,il+1) ) > 1 .AND. &
1041	( top_top_s(jl,il) - top_top_s(jl-1,il) ) > 1 .AND. &
1042	( zw(top_top_w(jl,il)) - &
1043	zw( top_top_w(jl-1,il+1) ) ) > .51_wp ) &
1044	THEN
1045	obstacle_flags(jl,il) = IBSET( obstacle_flags(jl,il), 3 )
1046	ENDIF
1047	ENDIF
1048	!
1049	!-- South edge
1050	IF ( jl > nysg ) THEN
1051	IF ( ( top_top_s(jl,il) - top_top_s(jl-1,il) ) > 1 .AND. &
1052	( zw( top_top_w(jl,il) ) - &
1053	zw( top_top_w(jl-1,il) ) ) > .51_wp ) &
1054	THEN
1055	obstacle_flags(jl,il) = IBSET( obstacle_flags(jl,il), 4 )
1056	ENDIF
1057	ENDIF
1058	!
1059	!-- South left corner
1060	IF ( jl > nysg .AND. il > nxlg ) THEN
1061	IF ( ( top_top_s(jl,il) - top_top_s(jl-1,il) ) > 1 .AND. &
1062	( top_top_s(jl,il) - top_top_s(jl-1,il-1) ) > 1 .AND. &
1063	( top_top_s(jl,il) - top_top_s(jl,il-1) ) > 1 .AND. &
1064	( zw( top_top_w(jl,il) ) - &
1065	zw(top_top_w(jl-1,il-1) ) ) > .51_wp ) &
1066	THEN
1067	obstacle_flags(jl,il) = IBSET( obstacle_flags(jl,il), 5 )
1068	ENDIF
1069	ENDIF
1070	!
1071	!-- Left edge
1072	IF ( il > nxlg ) THEN
1073	IF ( ( top_top_s(jl,il) - top_top_s(jl,il-1) ) > 1 .AND. &
1074	( zw(top_top_w(jl,il) ) - &
1075	zw(top_top_w(jl,il-1) ) ) > .51_wp ) &
1076	THEN
1077	obstacle_flags(jl,il) = IBSET( obstacle_flags(jl,il), 6 )
1078	ENDIF
1079	ENDIF
1080	!
1081	!-- North left corner
1082	IF ( jl < nyng .AND. il > nxlg ) THEN
1083	IF ( ( top_top_s(jl,il) - top_top_s(jl,il-1) ) > 1 .AND. &
1084	( top_top_s(jl,il) - top_top_s(jl+1,il-1) ) > 1 .AND. &
1085	( top_top_s(jl,il) - top_top_s(jl+1,il) ) > 1 .AND. &
1086	( zw( top_top_w(jl,il) ) - &
1087	zw( top_top_w(jl+1,il-1) ) ) > .51_wp ) &
1088	THEN
1089	obstacle_flags(jl,il) = IBSET( obstacle_flags(jl,il), 7 )
1090	ENDIF
1091	ENDIF
1092
1093	ENDDO
1094	ENDDO
1095
1096	END SUBROUTINE mas_create_obstacle_flags
1097
1098	!------------------------------------------------------------------------------!
1099	! Description:
1100	! ------------
1101	!> Write agent data in netCDF format
1102	!------------------------------------------------------------------------------!
1103	SUBROUTINE mas_data_output_agents( ftest )
1104
1105	USE control_parameters, &
1106	ONLY: agt_time_count
1107
1108	USE netcdf_interface, &
1109	ONLY: nc_stat, id_set_agt, id_var_time_agt, id_var_rnoa_agt, &
1110	id_var_agt, netcdf_handle_error
1111
1112	USE pegrid
1113
1114	#if defined( __netcdf )
1115	USE NETCDF
1116	#endif
1117
1118	IMPLICIT NONE
1119
1120	INTEGER(iwp) :: agt_size !< Agent size in bytes
1121	INTEGER(iwp) :: dummy !< dummy
1122	INTEGER(iwp) :: ip !< counter (x)
1123	INTEGER(iwp) :: jp !< counter (y)
1124	INTEGER(iwp) :: n !< counter (number of PEs)
1125	INTEGER(iwp) :: noa !< number of agents
1126	INTEGER(iwp) :: noa_rcv !< received number of agents
1127	INTEGER(iwp) :: out_noa !< number of agents for output
1128
1129	INTEGER(iwp), DIMENSION(0:numprocs-1) :: noa_arr !< number of agents on each PE
1130
1131	TYPE(agent_type), DIMENSION(:), ALLOCATABLE, TARGET :: trf_agents !< all agents on current PE
1132	TYPE(agent_type), DIMENSION(:), ALLOCATABLE, TARGET :: out_agents !< all agents in entire domain
1133	LOGICAL, INTENT (INOUT) :: ftest
1134
1135	CALL cpu_log( log_point_s(17), 'mas_data_output', 'start' )
1136	!
1137	!-- Get total number of agents and put all agents on one PE in one array
1138	noa = 0
1139	DO ip = nxl, nxr
1140	DO jp = nys, nyn
1141	noa = noa + agt_count(jp,ip)
1142	ENDDO
1143	ENDDO
1144	IF(noa > 0) THEN
1145	ALLOCATE(trf_agents(1:noa))
1146	dummy = 1
1147	DO ip = nxl, nxr
1148	DO jp = nys, nyn
1149	IF ( agt_count(jp,ip) == 0 ) CYCLE
1150	agents => grid_agents(jp,ip)%agents(1:agt_count(jp,ip))
1151	trf_agents(dummy:(dummy-1+agt_count(jp,ip))) = agents
1152	dummy = dummy + agt_count(jp,ip)
1153	ENDDO
1154	ENDDO
1155	ENDIF
1156	!
1157	!-- Gather all agents on PE0 for output
1158	CALL MPI_BARRIER( comm2d, ierr )
1159	IF ( myid == 0 ) THEN
1160	noa_arr(0) = noa
1161	!
1162	!-- Receive data from all other PEs.
1163	DO n = 1, numprocs-1
1164	CALL MPI_RECV( noa_arr(n), 1, MPI_INTEGER, &
1165	n, 0, comm2d, status, ierr )
1166	ENDDO
1167	ELSE
1168	CALL MPI_SEND( noa, 1, MPI_INTEGER, 0, 0, comm2d, ierr )
1169	ENDIF
1170	CALL MPI_BARRIER( comm2d, ierr )
1171	agt_size = STORAGE_SIZE(zero_agent)/8
1172	IF ( myid == 0 ) THEN
1173	!
1174	!-- Receive data from all other PEs.
1175	out_noa = SUM(noa_arr)
1176	IF ( out_noa > 0 ) THEN
1177	ALLOCATE( out_agents(1:out_noa) )
1178	IF ( noa > 0 ) THEN
1179	out_agents(1:noa) = trf_agents
1180	ENDIF
1181	noa_rcv = noa
1182	DO n = 1, numprocs-1
1183	IF ( noa_arr(n) > 0 ) THEN
1184	CALL MPI_RECV( out_agents(noa_rcv+1), noa_arr(n)*agt_size, &
1185	MPI_BYTE, n, 0, comm2d, status, ierr )
1186	noa_rcv = noa_rcv + noa_arr(n)
1187	ENDIF
1188	ENDDO
1189	ELSE
1190	ALLOCATE( out_agents(1:2) )
1191	out_agents = zero_agent
1192	out_noa = 2
1193	ENDIF
1194	ELSE
1195	IF ( noa > 0 ) THEN
1196	CALL MPI_SEND( trf_agents(1), noa*agt_size, MPI_BYTE, 0, 0, &
1197	comm2d, ierr )
1198	ENDIF
1199	ENDIF
1200	!
1201	!-- A barrier has to be set, because otherwise some PEs may
1202	!-- proceed too fast so that PE0 may receive wrong data on
1203	!-- tag 0
1204	CALL MPI_BARRIER( comm2d, ierr )
1205	IF ( myid == 0 ) THEN
1206	agents=>out_agents
1207
1208
1209	#if defined( __netcdf )
1210
1211	!-- Output in netCDF format
1212	IF ( ftest ) CALL check_open( 118 )
1213
1214	!
1215	!-- Update the NetCDF time axis
1216	agt_time_count = agt_time_count + 1
1217
1218	nc_stat = NF90_PUT_VAR( id_set_agt, id_var_time_agt, &
1219	(/ simulated_time /), &
1220	start = (/ agt_time_count /), count = (/ 1 /) )
1221	CALL netcdf_handle_error( 'mas_data_output_agents', 1 )
1222
1223	!
1224	!-- Output all agent attributes
1225	nc_stat = NF90_PUT_VAR( id_set_agt, id_var_agt(1), agents%x, &
1226	start = (/ 1, agt_time_count /), &
1227	count = (/ out_noa /) )
1228	CALL netcdf_handle_error( 'mas_data_output_agents', 3 )
1229
1230	nc_stat = NF90_PUT_VAR( id_set_agt, id_var_agt(2), agents%y, &
1231	start = (/ 1, agt_time_count /), &
1232	count = (/ out_noa /) )
1233	CALL netcdf_handle_error( 'mas_data_output_agents', 4 )
1234
1235	nc_stat = NF90_PUT_VAR( id_set_agt, id_var_agt(3), agents%windspeed, &
1236	start = (/ 1, agt_time_count /), &
1237	count = (/ out_noa /) )
1238	CALL netcdf_handle_error( 'mas_data_output_agents', 5 )
1239
1240	nc_stat = NF90_PUT_VAR( id_set_agt, id_var_agt(4), agents%t, &
1241	start = (/ 1, agt_time_count /), &
1242	count = (/ out_noa /) )
1243	CALL netcdf_handle_error( 'mas_data_output_agents', 6 )
1244
1245	nc_stat = NF90_PUT_VAR( id_set_agt, id_var_agt(5), agents%group, &
1246	start = (/ 1, agt_time_count /), &
1247	count = (/ out_noa /) )
1248	CALL netcdf_handle_error( 'mas_data_output_agents', 7 )
1249
1250	! nc_stat = NF90_PUT_VAR( id_set_agt, id_var_agt(6), agents%pm10, &
1251	! start = (/ 1, agt_time_count /), &
1252	! count = (/ out_noa /) )
1253	! CALL netcdf_handle_error( 'mas_data_output_agents', 8 )
1254	!
1255	! nc_stat = NF90_PUT_VAR( id_set_agt, id_var_agt(7), agents%pm25, &
1256	! start = (/ 1, agt_time_count /), &
1257	! count = (/ out_noa /) )
1258	! CALL netcdf_handle_error( 'mas_data_output_agents', 9 )
1259	!
1260	! nc_stat = NF90_PUT_VAR( id_set_agt, id_var_agt(8), agents%therm_comf,&
1261	! start = (/ 1, agt_time_count /), &
1262	! count = (/ out_noa /) )
1263	!
1264	! nc_stat = NF90_PUT_VAR( id_set_agt, id_var_agt(9), agents%uv, &
1265	! start = (/ 1, agt_time_count /), &
1266	! count = (/ out_noa /) )
1267	CALL netcdf_handle_error( 'mas_data_output_agents', 10 )
1268
1269	#endif
1270
1271	DEALLOCATE(out_agents)
1272	ENDIF
1273
1274	CALL cpu_log( log_point_s(17), 'mas_data_output', 'stop' )
1275
1276	END SUBROUTINE mas_data_output_agents
1277
1278	!------------------------------------------------------------------------------!
1279	! Description:
1280	! ------------
1281	!> If an agent moves from one processor to another, this subroutine moves
1282	!> the corresponding elements from the agent arrays of the old grid cells
1283	!> to the agent arrays of the new grid cells.
1284	!------------------------------------------------------------------------------!
1285	SUBROUTINE mas_eh_add_agents_to_gridcell (agent_array)
1286
1287	IMPLICIT NONE
1288
1289	INTEGER(iwp) :: aindex !< dummy argument for new number of agents per grid box
1290	INTEGER(iwp) :: ip !< grid index (x) of agent
1291	INTEGER(iwp) :: jp !< grid index (x) of agent
1292	INTEGER(iwp) :: n !< index variable of agent
1293
1294	LOGICAL :: pack_done !< flag to indicate that packing is done
1295
1296	TYPE(agent_type), DIMENSION(:), INTENT(IN) :: agent_array !< new agents in a grid box
1297	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: temp_ns !< temporary agent array for reallocation
1298
1299	pack_done = .FALSE.
1300
1301	DO n = 1, SIZE(agent_array)
1302
1303	IF ( .NOT. agent_array(n)%agent_mask ) CYCLE
1304
1305	ip = agent_array(n)%x * ddx
1306	jp = agent_array(n)%y * ddy
1307
1308	IF ( ip >= nxl .AND. ip <= nxr .AND. &
1309	jp >= nys .AND. jp <= nyn ) &
1310	THEN ! agent stays on processor
1311	number_of_agents = agt_count(jp,ip)
1312	agents => grid_agents(jp,ip)%agents(1:number_of_agents)
1313
1314	aindex = agt_count(jp,ip)+1
1315	IF( aindex > SIZE(grid_agents(jp,ip)%agents) ) THEN
1316	IF ( pack_done ) THEN
1317	CALL mas_eh_realloc_agents_array (ip,jp)
1318	ELSE
1319	CALL mas_ps_pack
1320	agt_count(jp,ip) = number_of_agents
1321	aindex = agt_count(jp,ip)+1
1322	IF ( aindex > SIZE(grid_agents(jp,ip)%agents) ) THEN
1323	CALL mas_eh_realloc_agents_array (ip,jp)
1324	ENDIF
1325	pack_done = .TRUE.
1326	ENDIF
1327	ENDIF
1328	grid_agents(jp,ip)%agents(aindex) = agent_array(n)
1329	agt_count(jp,ip) = aindex
1330	ELSE
1331	IF ( jp <= nys - 1 ) THEN
1332	nr_move_south = nr_move_south+1
1333	!
1334	!-- Before agent information is swapped to exchange-array, check
1335	!-- if enough memory is allocated. If required, reallocate exchange
1336	!-- array.
1337	IF ( nr_move_south > SIZE(move_also_south) ) THEN
1338	!
1339	!-- At first, allocate further temporary array to swap agent
1340	!-- information.
1341	ALLOCATE( temp_ns(SIZE(move_also_south)+NR_2_direction_move))
1342	temp_ns(1:nr_move_south-1) = move_also_south &
1343	(1:nr_move_south-1)
1344	DEALLOCATE( move_also_south )
1345	ALLOCATE( move_also_south(SIZE(temp_ns)) )
1346	move_also_south(1:nr_move_south-1) = temp_ns &
1347	(1:nr_move_south-1)
1348	DEALLOCATE( temp_ns )
1349
1350	ENDIF
1351
1352	move_also_south(nr_move_south) = agent_array(n)
1353
1354	IF ( jp == -1 ) THEN
1355	!
1356	!-- Apply boundary condition along y
1357	IF ( ibc_mas_ns == 0 ) THEN
1358	move_also_south(nr_move_south)%y = &
1359	move_also_south(nr_move_south)%y &
1360	+ ( ny + 1 ) * dy
1361	move_also_south(nr_move_south)%origin_y = &
1362	move_also_south(nr_move_south)%origin_y &
1363	+ ( ny + 1 ) * dy
1364	ELSEIF ( ibc_mas_ns == 1 ) THEN
1365	!
1366	!-- Agent absorption
1367	move_also_south(nr_move_south)%agent_mask = .FALSE.
1368	deleted_agents = deleted_agents + 1
1369
1370	ENDIF
1371	ENDIF
1372	ELSEIF ( jp >= nyn+1 ) THEN
1373	nr_move_north = nr_move_north+1
1374	!
1375	!-- Before agent information is swapped to exchange-array, check
1376	!-- if enough memory is allocated. If required, reallocate exchange
1377	!-- array.
1378	IF ( nr_move_north > SIZE(move_also_north) ) THEN
1379	!
1380	!-- At first, allocate further temporary array to swap agent
1381	!-- information.
1382	ALLOCATE( temp_ns(SIZE(move_also_north)+NR_2_direction_move))
1383	temp_ns(1:nr_move_north-1) = &
1384	move_also_south(1:nr_move_north-1)
1385	DEALLOCATE( move_also_north )
1386	ALLOCATE( move_also_north(SIZE(temp_ns)) )
1387	move_also_north(1:nr_move_north-1) = &
1388	temp_ns(1:nr_move_north-1)
1389	DEALLOCATE( temp_ns )
1390
1391	ENDIF
1392
1393	move_also_north(nr_move_north) = agent_array(n)
1394	IF ( jp == ny+1 ) THEN
1395	!
1396	!-- Apply boundary condition along y
1397	IF ( ibc_mas_ns == 0 ) THEN
1398
1399	move_also_north(nr_move_north)%y = &
1400	move_also_north(nr_move_north)%y &
1401	- ( ny + 1 ) * dy
1402	move_also_north(nr_move_north)%origin_y = &
1403	move_also_north(nr_move_north)%origin_y &
1404	- ( ny + 1 ) * dy
1405	ELSEIF ( ibc_mas_ns == 1 ) THEN
1406	!
1407	!-- Agent absorption
1408	move_also_north(nr_move_north)%agent_mask = .FALSE.
1409	deleted_agents = deleted_agents + 1
1410
1411	ENDIF
1412	ENDIF
1413	ENDIF
1414	ENDIF
1415	ENDDO
1416
1417	RETURN
1418
1419	END SUBROUTINE mas_eh_add_agents_to_gridcell
1420
1421	!------------------------------------------------------------------------------!
1422	! Description:
1423	! ------------
1424	!> After ghost layer agents have been received from neighboring PEs, this
1425	!> subroutine sorts them into the corresponding grid cells
1426	!------------------------------------------------------------------------------!
1427	SUBROUTINE mas_eh_add_ghost_agents_to_gridcell (agent_array)
1428
1429	IMPLICIT NONE
1430
1431	INTEGER(iwp) :: ip !< grid index (x) of agent
1432	INTEGER(iwp) :: jp !< grid index (x) of agent
1433	INTEGER(iwp) :: n !< index variable of agent
1434	INTEGER(iwp) :: aindex !< dummy argument for new number of agents per grid box
1435
1436	LOGICAL :: pack_done !< flag to indicate that packing is done
1437
1438	TYPE(agent_type), DIMENSION(:), INTENT(IN) :: agent_array !< new agents in a grid box
1439	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: temp_ns !< temporary agent array for reallocation
1440
1441	pack_done = .FALSE.
1442
1443	DO n = 1, SIZE(agent_array)
1444
1445	IF ( .NOT. agent_array(n)%agent_mask ) CYCLE
1446
1447	ip = agent_array(n)%x * ddx
1448	jp = agent_array(n)%y * ddy
1449
1450	IF ( ip < nxl .OR. ip > nxr .OR. jp < nys .OR. jp > nyn ) THEN
1451	number_of_agents = agt_count(jp,ip)
1452	agents => grid_agents(jp,ip)%agents(1:number_of_agents)
1453
1454	aindex = agt_count(jp,ip)+1
1455	IF( aindex > SIZE(grid_agents(jp,ip)%agents) ) THEN
1456	IF ( pack_done ) THEN
1457	CALL mas_eh_realloc_agents_array (ip,jp)
1458	ELSE
1459	CALL mas_ps_pack
1460	agt_count(jp,ip) = number_of_agents
1461	aindex = agt_count(jp,ip)+1
1462	IF ( aindex > SIZE(grid_agents(jp,ip)%agents) ) THEN
1463	CALL mas_eh_realloc_agents_array (ip,jp)
1464	ENDIF
1465	pack_done = .TRUE.
1466	ENDIF
1467	ENDIF
1468	grid_agents(jp,ip)%agents(aindex) = agent_array(n)
1469	agt_count(jp,ip) = aindex
1470	ENDIF
1471	ENDDO
1472	END SUBROUTINE mas_eh_add_ghost_agents_to_gridcell
1473
1474	!------------------------------------------------------------------------------!
1475	! Description:
1476	! ------------
1477	!> Resizing of agent arrays
1478	!------------------------------------------------------------------------------!
1479	SUBROUTINE mas_eh_dealloc_agents_array
1480
1481	IMPLICIT NONE
1482
1483	INTEGER(iwp) :: i !< grid index (x) of agent
1484	INTEGER(iwp) :: j !< grid index (y) of agent
1485	INTEGER(iwp) :: old_size !< old array size
1486	INTEGER(iwp) :: new_size !< new array size
1487	INTEGER(iwp) :: noa !< number of agents
1488
1489	LOGICAL :: dealloc !< flag that indicates if reallocation is necessary
1490
1491	TYPE(agent_type), DIMENSION(10) :: tmp_agents_s !< temporary static agent array
1492
1493	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: tmp_agents_d !< temporary dynamic agent array
1494
1495	DO i = nxlg, nxrg
1496	DO j = nysg, nyng
1497	!
1498	!-- Determine number of active agents
1499	noa = agt_count(j,i)
1500	!
1501	!-- Determine allocated memory size
1502	old_size = SIZE( grid_agents(j,i)%agents )
1503	!
1504	!-- Check for large unused memory
1505	dealloc = ( ( noa < min_nr_agent .AND. old_size > min_nr_agent ) &
1506	.OR. ( noa > min_nr_agent .AND. old_size - noa * &
1507	( 1.0_wp + 0.01_wp * alloc_factor_mas ) > 0.0_wp ) )
1508	!
1509	!-- If large unused memory was found, resize the corresponding array
1510	IF ( dealloc ) THEN
1511	IF ( noa < min_nr_agent ) THEN
1512	new_size = min_nr_agent
1513	ELSE
1514	new_size = INT( noa * ( 1.0_wp + &
1515	0.01_wp * alloc_factor_mas ) )
1516	ENDIF
1517
1518	IF ( noa <= 10 ) THEN
1519
1520	tmp_agents_s(1:noa) = grid_agents(j,i)%agents(1:noa)
1521
1522	DEALLOCATE(grid_agents(j,i)%agents)
1523	ALLOCATE(grid_agents(j,i)%agents(1:new_size))
1524
1525	grid_agents(j,i)%agents(1:noa) = tmp_agents_s(1:noa)
1526	grid_agents(j,i)%agents(noa+1:new_size) = zero_agent
1527
1528	ELSE
1529
1530	ALLOCATE(tmp_agents_d(noa))
1531	tmp_agents_d(1:noa) = grid_agents(j,i)%agents(1:noa)
1532
1533	DEALLOCATE(grid_agents(j,i)%agents)
1534	ALLOCATE(grid_agents(j,i)%agents(new_size))
1535
1536	grid_agents(j,i)%agents(1:noa) = tmp_agents_d(1:noa)
1537	grid_agents(j,i)%agents(noa+1:new_size) = zero_agent
1538
1539	DEALLOCATE(tmp_agents_d)
1540
1541	ENDIF
1542
1543	ENDIF
1544	ENDDO
1545	ENDDO
1546
1547	END SUBROUTINE mas_eh_dealloc_agents_array
1548
1549	!------------------------------------------------------------------------------!
1550	! Description:
1551	! ------------
1552	!> Exchange between subdomains.
1553	!> As soon as one agent has moved beyond the boundary of the domain, it
1554	!> is included in the relevant transfer arrays and marked for subsequent
1555	!> deletion on this PE.
1556	!> First sweep for crossings in x direction. Find out first the number of
1557	!> agents to be transferred and allocate temporary arrays needed to store
1558	!> them.
1559	!> For a one-dimensional decomposition along y, no transfer is necessary,
1560	!> because the agent remains on the PE, but the agent coordinate has to
1561	!> be adjusted.
1562	!------------------------------------------------------------------------------!
1563	SUBROUTINE mas_eh_exchange_horiz
1564
1565	IMPLICIT NONE
1566
1567	INTEGER(iwp) :: i !< grid index (x) of agent positition
1568	INTEGER(iwp) :: ip !< index variable along x
1569	INTEGER(iwp) :: j !< grid index (y) of agent positition
1570	INTEGER(iwp) :: jp !< index variable along y
1571	INTEGER(iwp) :: kp !< index variable along z
1572	INTEGER(iwp) :: n !< agent index variable
1573	INTEGER(iwp) :: par_size !< Agent size in bytes
1574	INTEGER(iwp) :: trla_count !< number of agents send to left PE
1575	INTEGER(iwp) :: trla_count_recv !< number of agents receive from right PE
1576	INTEGER(iwp) :: trna_count !< number of agents send to north PE
1577	INTEGER(iwp) :: trna_count_recv !< number of agents receive from south PE
1578	INTEGER(iwp) :: trra_count !< number of agents send to right PE
1579	INTEGER(iwp) :: trra_count_recv !< number of agents receive from left PE
1580	INTEGER(iwp) :: trsa_count !< number of agents send to south PE
1581	INTEGER(iwp) :: trsa_count_recv !< number of agents receive from north PE
1582
1583	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: rvla !< agents received from right PE
1584	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: rvna !< agents received from south PE
1585	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: rvra !< agents received from left PE
1586	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: rvsa !< agents received from north PE
1587	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: trla !< agents send to left PE
1588	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: trna !< agents send to north PE
1589	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: trra !< agents send to right PE
1590	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: trsa !< agents send to south PE
1591
1592	CALL cpu_log( log_point_s(18), 'mas_eh_exchange_horiz', 'start' )
1593
1594	#if defined( __parallel )
1595
1596	!
1597	!-- Exchange between subdomains.
1598	!-- As soon as one agent has moved beyond the boundary of the domain, it
1599	!-- is included in the relevant transfer arrays and marked for subsequent
1600	!-- deletion on this PE.
1601	!-- First sweep for crossings in x direction. Find out first the number of
1602	!-- agents to be transferred and allocate temporary arrays needed to store
1603	!-- them.
1604	!-- For a one-dimensional decomposition along y, no transfer is necessary,
1605	!-- because the agent remains on the PE, but the agent coordinate has to
1606	!-- be adjusted.
1607	trla_count = 0
1608	trra_count = 0
1609
1610	trla_count_recv = 0
1611	trra_count_recv = 0
1612
1613	IF ( pdims(1) /= 1 ) THEN
1614	!
1615	!-- First calculate the storage necessary for sending and receiving the data.
1616	!-- Compute only first (nxl) and last (nxr) loop iterration.
1617	DO ip = nxl, nxr, nxr - nxl
1618	DO jp = nys, nyn
1619
1620	number_of_agents = agt_count(jp,ip)
1621	IF ( number_of_agents <= 0 ) CYCLE
1622	agents => grid_agents(jp,ip)%agents(1:number_of_agents)
1623	DO n = 1, number_of_agents
1624	IF ( agents(n)%agent_mask ) THEN
1625	i = agents(n)%x * ddx
1626	!
1627	!-- Above calculation does not work for indices less than zero
1628	IF ( agents(n)%x < 0.0_wp ) i = -1
1629
1630	IF ( i < nxl ) THEN
1631	trla_count = trla_count + 1
1632	ELSEIF ( i > nxr ) THEN
1633	trra_count = trra_count + 1
1634	ENDIF
1635	ENDIF
1636	ENDDO
1637
1638	ENDDO
1639	ENDDO
1640
1641	IF ( trla_count == 0 ) trla_count = 1
1642	IF ( trra_count == 0 ) trra_count = 1
1643
1644	ALLOCATE( trla(trla_count), trra(trra_count) )
1645
1646	trla = zero_agent
1647	trra = zero_agent
1648
1649	trla_count = 0
1650	trra_count = 0
1651
1652	ENDIF
1653	!
1654	!-- Compute only first (nxl) and last (nxr) loop iterration
1655	DO ip = nxl, nxr, nxr-nxl
1656	DO jp = nys, nyn
1657	number_of_agents = agt_count(jp,ip)
1658	IF ( number_of_agents <= 0 ) CYCLE
1659	agents => grid_agents(jp,ip)%agents(1:number_of_agents)
1660	DO n = 1, number_of_agents
1661	!
1662	!-- Only those agents that have not been marked as 'deleted' may
1663	!-- be moved.
1664	IF ( agents(n)%agent_mask ) THEN
1665
1666	i = agents(n)%x * ddx
1667	!
1668	!-- Above calculation does not work for indices less than zero
1669	IF ( agents(n)%x < 0.0_wp ) i = -1
1670
1671	IF ( i < nxl ) THEN
1672	IF ( i < 0 ) THEN
1673	!
1674	!-- Apply boundary condition along x
1675	IF ( ibc_mas_lr == 0 ) THEN
1676	!
1677	!-- Cyclic condition
1678	IF ( pdims(1) == 1 ) THEN
1679	agents(n)%x = ( nx + 1 ) * dx + &
1680	agents(n)%x
1681	agents(n)%origin_x = ( nx + 1 ) * dx + &
1682	agents(n)%origin_x
1683	ELSE
1684	trla_count = trla_count + 1
1685	trla(trla_count) = agents(n)
1686	trla(trla_count)%x = ( nx + 1 ) * dx + &
1687	trla(trla_count)%x
1688	trla(trla_count)%origin_x = &
1689	trla(trla_count)%origin_x + &
1690	( nx + 1 ) * dx
1691	agents(n)%agent_mask = .FALSE.
1692	deleted_agents = deleted_agents + 1
1693
1694	IF ( trla(trla_count)%x >= &
1695	(nx + 1)* dx - 1.0E-12_wp ) &
1696	THEN
1697	trla(trla_count)%x = trla(trla_count)%x - &
1698	1.0E-10_wp
1699	trla(trla_count)%origin_x = &
1700	trla(trla_count)%origin_x - 1
1701	ENDIF
1702
1703	ENDIF
1704
1705	ELSEIF ( ibc_mas_lr == 1 ) THEN
1706	!
1707	!-- Agent absorption
1708	agents(n)%agent_mask = .FALSE.
1709	deleted_agents = deleted_agents + 1
1710
1711	ENDIF
1712	ELSE
1713	!
1714	!-- Store agent data in the transfer array, which will be
1715	!-- send to the neighbouring PE
1716	trla_count = trla_count + 1
1717	trla(trla_count) = agents(n)
1718	agents(n)%agent_mask = .FALSE.
1719	deleted_agents = deleted_agents + 1
1720
1721	ENDIF
1722
1723	ELSEIF ( i > nxr ) THEN
1724	IF ( i > nx ) THEN
1725	!
1726	!-- Apply boundary condition along x
1727	IF ( ibc_mas_lr == 0 ) THEN
1728	!
1729	!-- Cyclic condition
1730	IF ( pdims(1) == 1 ) THEN
1731	agents(n)%x = agents(n)%x - ( nx + 1 ) * dx
1732	agents(n)%origin_x = agents(n)%origin_x - &
1733	( nx + 1 ) * dx
1734	ELSE
1735	trra_count = trra_count + 1
1736	trra(trra_count) = agents(n)
1737	trra(trra_count)%x = trra(trra_count)%x - &
1738	( nx + 1 ) * dx
1739	trra(trra_count)%origin_x = &
1740	trra(trra_count)%origin_x - &
1741	( nx + 1 ) * dx
1742	agents(n)%agent_mask = .FALSE.
1743	deleted_agents = deleted_agents + 1
1744
1745	ENDIF
1746
1747	ELSEIF ( ibc_mas_lr == 1 ) THEN
1748	!
1749	!-- Agent absorption
1750	agents(n)%agent_mask = .FALSE.
1751	deleted_agents = deleted_agents + 1
1752
1753	ENDIF
1754	ELSE
1755	!
1756	!-- Store agent data in the transfer array, which will be send
1757	!-- to the neighbouring PE
1758	trra_count = trra_count + 1
1759	trra(trra_count) = agents(n)
1760	agents(n)%agent_mask = .FALSE.
1761	deleted_agents = deleted_agents + 1
1762
1763	ENDIF
1764
1765	ENDIF
1766	ENDIF
1767
1768	ENDDO
1769	ENDDO
1770	ENDDO
1771
1772	!
1773	!-- Allocate arrays required for north-south exchange, as these
1774	!-- are used directly after agents are exchange along x-direction.
1775	ALLOCATE( move_also_north(1:NR_2_direction_move) )
1776	ALLOCATE( move_also_south(1:NR_2_direction_move) )
1777
1778	nr_move_north = 0
1779	nr_move_south = 0
1780	!
1781	!-- Send left boundary, receive right boundary (but first exchange how many
1782	!-- and chec if agent storage must be extended)
1783	IF ( pdims(1) /= 1 ) THEN
1784
1785	CALL MPI_SENDRECV( trla_count, 1, MPI_INTEGER, pleft, 0, &
1786	trra_count_recv, 1, MPI_INTEGER, pright, 0, &
1787	comm2d, status, ierr )
1788
1789	ALLOCATE(rvra(MAX(1,trra_count_recv)))
1790	!
1791	!-- This MPI_SENDRECV should work even with odd mixture on 32 and 64 Bit
1792	!-- variables in structure agent_type (due to the calculation of par_size)
1793	par_size = STORAGE_SIZE(trla(1))/8
1794	CALL MPI_SENDRECV( trla, max(1,trla_count)*par_size, MPI_BYTE, pleft,&
1795	1, rvra, max(1,trra_count_recv)*par_size, MPI_BYTE, pright,&
1796	1, comm2d, status, ierr )
1797
1798	IF ( trra_count_recv > 0 ) THEN
1799	CALL mas_eh_add_agents_to_gridcell(rvra(1:trra_count_recv))
1800	ENDIF
1801
1802	DEALLOCATE(rvra)
1803
1804	!
1805	!-- Send right boundary, receive left boundary
1806	CALL MPI_SENDRECV( trra_count, 1, MPI_INTEGER, pright, 0, &
1807	trla_count_recv, 1, MPI_INTEGER, pleft, 0, &
1808	comm2d, status, ierr )
1809
1810	ALLOCATE(rvla(MAX(1,trla_count_recv)))
1811	!
1812	!-- This MPI_SENDRECV should work even with odd mixture on 32 and 64 Bit
1813	!-- variables in structure agent_type (due to the calculation of par_size)
1814	par_size = STORAGE_SIZE(trra(1))/8
1815	CALL MPI_SENDRECV( trra, max(1,trra_count)*par_size, MPI_BYTE, &
1816	pright, 1, rvla, &
1817	max(1,trla_count_recv)*par_size, MPI_BYTE, &
1818	pleft, 1, comm2d, status, ierr )
1819
1820	IF ( trla_count_recv > 0 ) THEN
1821	CALL mas_eh_add_agents_to_gridcell(rvla(1:trla_count_recv))
1822	ENDIF
1823
1824	DEALLOCATE( rvla )
1825	DEALLOCATE( trla, trra )
1826
1827	ENDIF
1828
1829	!
1830	!-- Check whether agents have crossed the boundaries in y direction. Note
1831	!-- that this case can also apply to agents that have just been received
1832	!-- from the adjacent right or left PE.
1833	!-- Find out first the number of agents to be transferred and allocate
1834	!-- temporary arrays needed to store them.
1835	!-- For a one-dimensional decomposition along y, no transfer is necessary,
1836	!-- because the agent remains on the PE.
1837	trsa_count = nr_move_south
1838	trna_count = nr_move_north
1839
1840	trsa_count_recv = 0
1841	trna_count_recv = 0
1842
1843	IF ( pdims(2) /= 1 ) THEN
1844	!
1845	!-- First calculate the storage necessary for sending and receiving the
1846	!-- data
1847	DO ip = nxl, nxr
1848	DO jp = nys, nyn, nyn-nys !compute only first (nys) and last (nyn) loop iterration
1849	number_of_agents = agt_count(jp,ip)
1850	IF ( number_of_agents <= 0 ) CYCLE
1851	agents => grid_agents(jp,ip)%agents(1:number_of_agents)
1852	DO n = 1, number_of_agents
1853	IF ( agents(n)%agent_mask ) THEN
1854	j = agents(n)%y * ddy
1855	!
1856	!-- Above calculation does not work for indices less than zero
1857	IF ( agents(n)%y < 0.0_wp ) j = -1
1858
1859	IF ( j < nys ) THEN
1860	trsa_count = trsa_count + 1
1861	ELSEIF ( j > nyn ) THEN
1862	trna_count = trna_count + 1
1863	ENDIF
1864	ENDIF
1865	ENDDO
1866	ENDDO
1867	ENDDO
1868
1869	IF ( trsa_count == 0 ) trsa_count = 1
1870	IF ( trna_count == 0 ) trna_count = 1
1871
1872	ALLOCATE( trsa(trsa_count), trna(trna_count) )
1873
1874	trsa = zero_agent
1875	trna = zero_agent
1876
1877	trsa_count = nr_move_south
1878	trna_count = nr_move_north
1879
1880	trsa(1:nr_move_south) = move_also_south(1:nr_move_south)
1881	trna(1:nr_move_north) = move_also_north(1:nr_move_north)
1882
1883	ENDIF
1884
1885	DO ip = nxl, nxr
1886	DO jp = nys, nyn, nyn-nys ! compute only first (nys) and last (nyn) loop iterration
1887	number_of_agents = agt_count(jp,ip)
1888	IF ( number_of_agents <= 0 ) CYCLE
1889	agents => grid_agents(jp,ip)%agents(1:number_of_agents)
1890	DO n = 1, number_of_agents
1891	!
1892	!-- Only those agents that have not been marked as 'deleted' may
1893	!-- be moved.
1894	IF ( agents(n)%agent_mask ) THEN
1895
1896	j = agents(n)%y * ddy
1897	!
1898	!-- Above calculation does not work for indices less than zero
1899	IF ( agents(n)%y < 0.0_wp * dy ) j = -1
1900
1901	IF ( j < nys ) THEN
1902	IF ( j < 0 ) THEN
1903	!
1904	!-- Apply boundary condition along y
1905	IF ( ibc_mas_ns == 0 ) THEN
1906	!
1907	!-- Cyclic condition
1908	IF ( pdims(2) == 1 ) THEN
1909	agents(n)%y = ( ny + 1 ) * dy + agents(n)%y
1910	agents(n)%origin_y = ( ny + 1 ) * dy + &
1911	agents(n)%origin_y
1912	ELSE
1913	trsa_count = trsa_count + 1
1914	trsa(trsa_count) = agents(n)
1915	trsa(trsa_count)%y = ( ny + 1 ) * dy + &
1916	trsa(trsa_count)%y
1917	trsa(trsa_count)%origin_y = &
1918	trsa(trsa_count)%origin_y &
1919	+ ( ny + 1 ) * dy
1920	agents(n)%agent_mask = .FALSE.
1921	deleted_agents = deleted_agents + 1
1922
1923	IF ( trsa(trsa_count)%y >= &
1924	(ny+1)* dy - 1.0E-12_wp ) &
1925	THEN
1926	trsa(trsa_count)%y = trsa(trsa_count)%y - &
1927	1.0E-10_wp
1928	trsa(trsa_count)%origin_y = &
1929	trsa(trsa_count)%origin_y - 1
1930	ENDIF
1931
1932	ENDIF
1933
1934	ELSEIF ( ibc_mas_ns == 1 ) THEN
1935	!
1936	!-- Agent absorption
1937	agents(n)%agent_mask = .FALSE.
1938	deleted_agents = deleted_agents + 1
1939
1940	ENDIF
1941	ELSE
1942	!
1943	!-- Store agent data in the transfer array, which will
1944	!-- be send to the neighbouring PE
1945	trsa_count = trsa_count + 1
1946	trsa(trsa_count) = agents(n)
1947	agents(n)%agent_mask = .FALSE.
1948	deleted_agents = deleted_agents + 1
1949
1950	ENDIF
1951
1952	ELSEIF ( j > nyn ) THEN
1953	IF ( j > ny ) THEN
1954	!
1955	!-- Apply boundary condition along y
1956	IF ( ibc_mas_ns == 0 ) THEN
1957	!
1958	!-- Cyclic condition
1959	IF ( pdims(2) == 1 ) THEN
1960	agents(n)%y = agents(n)%y - &
1961	( ny + 1 ) * dy
1962	agents(n)%origin_y = agents(n)%origin_y - &
1963	( ny + 1 ) * dy
1964	ELSE
1965	trna_count = trna_count + 1
1966	trna(trna_count) = agents(n)
1967	trna(trna_count)%y = &
1968	trna(trna_count)%y - ( ny + 1 ) * dy
1969	trna(trna_count)%origin_y = &
1970	trna(trna_count)%origin_y - &
1971	( ny + 1 ) * dy
1972	agents(n)%agent_mask = .FALSE.
1973	deleted_agents = deleted_agents + 1
1974	ENDIF
1975
1976	ELSEIF ( ibc_mas_ns == 1 ) THEN
1977	!
1978	!-- Agent absorption
1979	agents(n)%agent_mask = .FALSE.
1980	deleted_agents = deleted_agents + 1
1981
1982	ENDIF
1983	ELSE
1984	!
1985	!-- Store agent data in the transfer array, which will
1986	!-- be send to the neighbouring PE
1987	trna_count = trna_count + 1
1988	trna(trna_count) = agents(n)
1989	agents(n)%agent_mask = .FALSE.
1990	deleted_agents = deleted_agents + 1
1991
1992	ENDIF
1993
1994	ENDIF
1995	ENDIF
1996	ENDDO
1997	ENDDO
1998	ENDDO
1999
2000	!
2001	!-- Send front boundary, receive back boundary (but first exchange how many
2002	!-- and chec if agent storage must be extended)
2003	IF ( pdims(2) /= 1 ) THEN
2004
2005	CALL MPI_SENDRECV( trsa_count, 1, MPI_INTEGER, psouth, 0, &
2006	trna_count_recv, 1, MPI_INTEGER, pnorth, 0, &
2007	comm2d, status, ierr )
2008
2009	ALLOCATE(rvna(MAX(1,trna_count_recv)))
2010	!
2011	!-- This MPI_SENDRECV should work even with odd mixture on 32 and 64 Bit
2012	!-- variables in structure agent_type (due to the calculation of par_size)
2013	par_size = STORAGE_SIZE(trsa(1))/8
2014	CALL MPI_SENDRECV( trsa, trsa_count*par_size, MPI_BYTE, &
2015	psouth, 1, rvna, &
2016	trna_count_recv*par_size, MPI_BYTE, pnorth, 1, &
2017	comm2d, status, ierr )
2018
2019	IF ( trna_count_recv > 0 ) THEN
2020	CALL mas_eh_add_agents_to_gridcell(rvna(1:trna_count_recv))
2021	ENDIF
2022
2023	DEALLOCATE(rvna)
2024
2025	!
2026	!-- Send back boundary, receive front boundary
2027	CALL MPI_SENDRECV( trna_count, 1, MPI_INTEGER, pnorth, 0, &
2028	trsa_count_recv, 1, MPI_INTEGER, psouth, 0, &
2029	comm2d, status, ierr )
2030
2031	ALLOCATE(rvsa(MAX(1,trsa_count_recv)))
2032	!
2033	!-- This MPI_SENDRECV should work even with odd mixture on 32 and 64 Bit
2034	!-- variables in structure agent_type (due to the calculation of par_size)
2035	par_size = STORAGE_SIZE(trna(1))/8
2036	CALL MPI_SENDRECV( trna, trna_count*par_size, MPI_BYTE, &
2037	pnorth, 1, rvsa, &
2038	trsa_count_recv*par_size, MPI_BYTE, psouth, 1, &
2039	comm2d, status, ierr )
2040
2041	IF ( trsa_count_recv > 0 ) THEN
2042	CALL mas_eh_add_agents_to_gridcell(rvsa(1:trsa_count_recv))
2043	ENDIF
2044
2045	DEALLOCATE(rvsa)
2046
2047	number_of_agents = number_of_agents + trsa_count_recv
2048
2049	DEALLOCATE( trsa, trna )
2050
2051	ENDIF
2052
2053	DEALLOCATE( move_also_north )
2054	DEALLOCATE( move_also_south )
2055
2056	#else
2057
2058	DO ip = nxl, nxr, nxr-nxl
2059	DO jp = nys, nyn
2060	number_of_agents = agt_count(jp,ip)
2061	IF ( number_of_agents <= 0 ) CYCLE
2062	agents => grid_agents(jp,ip)%agents(1:number_of_agents)
2063	DO n = 1, number_of_agents
2064	!
2065	!-- Apply boundary conditions
2066	IF ( agents(n)%x < 0.0_wp ) THEN
2067
2068	IF ( ibc_mas_lr == 0 ) THEN
2069	!
2070	!-- Cyclic boundary. Relevant coordinate has to be changed.
2071	agents(n)%x = ( nx + 1 ) * dx + agents(n)%x
2072	agents(n)%origin_x = ( nx + 1 ) * dx + &
2073	agents(n)%origin_x
2074	ELSEIF ( ibc_mas_lr == 1 ) THEN
2075	!
2076	!-- Agent absorption
2077	agents(n)%agent_mask = .FALSE.
2078	deleted_agents = deleted_agents + 1
2079	ENDIF
2080
2081	ELSEIF ( agents(n)%x >= ( nx + 1 ) * dx ) THEN
2082
2083	IF ( ibc_mas_lr == 0 ) THEN
2084	!
2085	!-- Cyclic boundary. Relevant coordinate has to be changed.
2086	agents(n)%x = agents(n)%x - ( nx + 1 ) * dx
2087
2088	ELSEIF ( ibc_mas_lr == 1 ) THEN
2089	!
2090	!-- Agent absorption
2091	agents(n)%agent_mask = .FALSE.
2092	deleted_agents = deleted_agents + 1
2093	ENDIF
2094
2095	ENDIF
2096	ENDDO
2097	ENDDO
2098	ENDDO
2099
2100	DO ip = nxl, nxr
2101	DO jp = nys, nyn, nyn-nys
2102	number_of_agents = agt_count(jp,ip)
2103	IF ( number_of_agents <= 0 ) CYCLE
2104	agents => grid_agents(jp,ip)%agents(1:number_of_agents)
2105	DO n = 1, number_of_agents
2106
2107	IF ( agents(n)%y < 0.0_wp ) THEN
2108
2109	IF ( ibc_mas_ns == 0 ) THEN
2110	!
2111	!-- Cyclic boundary. Relevant coordinate has to be changed.
2112	agents(n)%y = ( ny + 1 ) * dy + agents(n)%y
2113	agents(n)%origin_y = ( ny + 1 ) * dy + &
2114	agents(n)%origin_y
2115
2116	ELSEIF ( ibc_mas_ns == 1 ) THEN
2117	!
2118	!-- Agent absorption
2119	agents(n)%agent_mask = .FALSE.
2120	deleted_agents = deleted_agents + 1
2121	ENDIF
2122
2123	ELSEIF ( agents(n)%y >= ( ny + 0.5_wp ) * dy ) THEN
2124
2125	IF ( ibc_mas_ns == 0 ) THEN
2126	!
2127	!-- Cyclic boundary. Relevant coordinate has to be changed.
2128	agents(n)%y = agents(n)%y - ( ny + 1 ) * dy
2129
2130	ELSEIF ( ibc_mas_ns == 1 ) THEN
2131	!
2132	!-- Agent absorption
2133	agents(n)%agent_mask = .FALSE.
2134	deleted_agents = deleted_agents + 1
2135	ENDIF
2136
2137	ENDIF
2138
2139	ENDDO
2140	ENDDO
2141	ENDDO
2142	#endif
2143
2144	!
2145	!-- Accumulate the number of agents transferred between the subdomains
2146	#if defined( __parallel )
2147	CALL mas_eh_ghost_exchange
2148	#endif
2149
2150	CALL cpu_log( log_point_s(18), 'mas_eh_exchange_horiz', 'stop' )
2151
2152	END SUBROUTINE mas_eh_exchange_horiz
2153
2154	!------------------------------------------------------------------------------!
2155	! Description:
2156	! ------------
2157	!> Sends the agents from the three gridcells closest to the
2158	!> north/south/left/right border of a PE to the corresponding neighbors ghost
2159	!> layer (which is three grid boxes deep)
2160	!------------------------------------------------------------------------------!
2161	SUBROUTINE mas_eh_ghost_exchange
2162
2163	IMPLICIT NONE
2164
2165	INTEGER(iwp) :: i !< grid index (x) of agent positition
2166	INTEGER(iwp) :: ip !< index variable along x
2167	INTEGER(iwp) :: j !< grid index (y) of agent positition
2168	INTEGER(iwp) :: jp !< index variable along y
2169	INTEGER(iwp) :: agt_size !< Bit size of agent datatype
2170	INTEGER(iwp) :: ghla_count !< ghost points left agent
2171	INTEGER(iwp) :: ghna_count !< ghost points north agent
2172	INTEGER(iwp) :: ghra_count !< ghost points right agent
2173	INTEGER(iwp) :: ghsa_count !< ghost points south agent
2174
2175	LOGICAL :: ghla_empty !< ghost points left agent
2176	LOGICAL :: ghla_empty_rcv !< ghost points left agent
2177	LOGICAL :: ghna_empty !< ghost points north agent
2178	LOGICAL :: ghna_empty_rcv !< ghost points north agent
2179	LOGICAL :: ghra_empty !< ghost points right agent
2180	LOGICAL :: ghra_empty_rcv !< ghost points right agent
2181	LOGICAL :: ghsa_empty !< ghost points south agent
2182	LOGICAL :: ghsa_empty_rcv !< ghost points south agent
2183
2184	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: ghla !< agents received from right PE
2185	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: ghna !< agents received from south PE
2186	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: ghra !< agents received from left PE
2187	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: ghsa !< agents received from north PE
2188
2189	ghla_empty = .TRUE.
2190	ghna_empty = .TRUE.
2191	ghra_empty = .TRUE.
2192	ghsa_empty = .TRUE.
2193	!
2194	!-- reset ghost layer
2195	DO ip = nxlg, nxl-1
2196	DO jp = nysg, nyng
2197	agt_count(jp,ip) = 0
2198	ENDDO
2199	ENDDO
2200	DO ip = nxr+1, nxrg
2201	DO jp = nysg, nyng
2202	agt_count(jp,ip) = 0
2203	ENDDO
2204	ENDDO
2205	DO ip = nxl, nxr
2206	DO jp = nysg, nys-1
2207	agt_count(jp,ip) = 0
2208	ENDDO
2209	ENDDO
2210	DO ip = nxl, nxr
2211	DO jp = nyn+1, nyng
2212	agt_count(jp,ip) = 0
2213	ENDDO
2214	ENDDO
2215	!
2216	!-- Transfer of agents from left to right and vice versa
2217	IF ( pdims(1) /= 1 ) THEN
2218	!
2219	!-- Reset left and right ghost layers
2220	ghla_count = 0
2221	ghra_count = 0
2222	!
2223	!-- First calculate the storage necessary for sending
2224	!-- and receiving the data.
2225	ghla_count = SUM(agt_count(nys:nyn,nxl:nxl+2))
2226	ghra_count = SUM(agt_count(nys:nyn,nxr-2:nxr))
2227	!
2228	!-- No cyclic boundaries for agents
2229	IF ( nxl == 0 .OR. ghla_count == 0 ) THEN
2230	ghla_count = 1
2231	ELSE
2232	ghla_empty = .FALSE.
2233	ENDIF
2234	IF ( nxr == nx .OR. ghra_count == 0 ) THEN
2235	ghra_count = 1
2236	ELSE
2237	ghra_empty = .FALSE.
2238	ENDIF
2239	ALLOCATE( ghla(1:ghla_count), ghra(1:ghra_count) )
2240	ghla = zero_agent
2241	ghra = zero_agent
2242	!
2243	!-- Get all agents that will be sent left into one array
2244	ghla_count = 0
2245	IF ( nxl /= 0 ) THEN
2246	DO ip = nxl, nxl+2
2247	DO jp = nys, nyn
2248
2249	number_of_agents = agt_count(jp,ip)
2250	IF ( number_of_agents <= 0 ) CYCLE
2251	ghla(ghla_count+1:ghla_count+number_of_agents) &
2252	= grid_agents(jp,ip)%agents(1:number_of_agents)
2253	ghla_count = ghla_count + number_of_agents
2254
2255	ENDDO
2256	ENDDO
2257	ENDIF
2258	IF ( ghla_count == 0 ) ghla_count = 1
2259	!
2260	!-- Get all agents that will be sent right into one array
2261	ghra_count = 0
2262	IF ( nxr /= nx ) THEN
2263	DO ip = nxr-2, nxr
2264	DO jp = nys, nyn
2265
2266	number_of_agents = agt_count(jp,ip)
2267	IF ( number_of_agents <= 0 ) CYCLE
2268	ghra(ghra_count+1:ghra_count+number_of_agents) &
2269	= grid_agents(jp,ip)%agents(1:number_of_agents)
2270	ghra_count = ghra_count + number_of_agents
2271
2272	ENDDO
2273	ENDDO
2274	ENDIF
2275	IF ( ghra_count == 0 ) ghra_count = 1
2276	!
2277	!-- Send/receive number of agents that
2278	!-- will be transferred to/from left/right neighbor
2279	CALL MPI_SENDRECV( ghla_count, 1, MPI_INTEGER, pleft, 0, &
2280	ghra_count_recv, 1, MPI_INTEGER, pright, 0, &
2281	comm2d, status, ierr )
2282	ALLOCATE ( agt_gh_r(1:ghra_count_recv) )
2283	!
2284	!-- Send/receive number of agents that
2285	!-- will be transferred to/from right/left neighbor
2286	CALL MPI_SENDRECV( ghra_count, 1, MPI_INTEGER, pright, 0, &
2287	ghla_count_recv, 1, MPI_INTEGER, pleft, 0, &
2288	comm2d, status, ierr )
2289	!
2290	!-- Send/receive flag that indicates if there are actually any agents
2291	!-- in ghost layer
2292	CALL MPI_SENDRECV( ghla_empty, 1, MPI_LOGICAL, pleft, 1, &
2293	ghra_empty_rcv, 1, MPI_LOGICAL, pright,1, &
2294	comm2d, status, ierr )
2295	CALL MPI_SENDRECV( ghra_empty, 1, MPI_LOGICAL, pright,1, &
2296	ghla_empty_rcv, 1, MPI_LOGICAL, pleft, 1, &
2297	comm2d, status, ierr )
2298
2299
2300	ALLOCATE ( agt_gh_l(1:ghla_count_recv) )
2301	!
2302	!-- Get bit size of one agent
2303	agt_size = STORAGE_SIZE(zero_agent)/8
2304	!
2305	!-- Send/receive agents to/from left/right neighbor
2306	CALL MPI_SENDRECV( ghla, ghla_count * agt_size, MPI_BYTE, &
2307	pleft, 1, &
2308	agt_gh_r, ghra_count_recv * agt_size, MPI_BYTE, &
2309	pright,1, &
2310	comm2d, status, ierr )
2311	!
2312	!-- Send/receive agents to/from left/right neighbor
2313	CALL MPI_SENDRECV( ghra, ghra_count * agt_size, MPI_BYTE, &
2314	pright,1, &
2315	agt_gh_l, ghla_count_recv * agt_size, MPI_BYTE, &
2316	pleft, 1, &
2317	comm2d, status, ierr )
2318	!
2319	!-- If agents were received, add them to the respective ghost layer cells
2320	IF ( .NOT. ghra_empty_rcv ) THEN
2321	CALL mas_eh_add_ghost_agents_to_gridcell(agt_gh_r)
2322	ENDIF
2323
2324	IF ( .NOT. ghla_empty_rcv ) THEN
2325	CALL mas_eh_add_ghost_agents_to_gridcell(agt_gh_l)
2326	ENDIF
2327
2328	DEALLOCATE( ghla, ghra, agt_gh_l, agt_gh_r )
2329
2330	ENDIF
2331
2332	!
2333	!-- Transfer of agents from south to north and vice versa
2334	IF ( pdims(2) /= 1 ) THEN
2335	!
2336	!-- Reset south and north ghost layers
2337	ghsa_count = 0
2338	ghna_count = 0
2339	!
2340	!-- First calculate the storage necessary for sending
2341	!-- and receiving the data.
2342	ghsa_count = SUM(agt_count(nys:nys+2,nxlg:nxrg))
2343	ghna_count = SUM(agt_count(nyn-2:nyn,nxlg:nxrg))
2344	!
2345	!-- No cyclic boundaries for agents
2346	IF ( nys == 0 .OR. ghsa_count == 0 ) THEN
2347	ghsa_count = 1
2348	ELSE
2349	ghsa_empty = .FALSE.
2350	ENDIF
2351	IF ( nyn == ny .OR. ghna_count == 0 ) THEN
2352	ghna_count = 1
2353	ELSE
2354	ghna_empty = .FALSE.
2355	ENDIF
2356	ALLOCATE( ghsa(1:ghsa_count), ghna(1:ghna_count) )
2357	ghsa = zero_agent
2358	ghna = zero_agent
2359	!
2360	!-- Get all agents that will be sent south into one array
2361	ghsa_count = 0
2362	IF ( nys /= 0 ) THEN
2363	DO ip = nxlg, nxrg
2364	DO jp = nys, nys+2
2365
2366	number_of_agents = agt_count(jp,ip)
2367	IF ( number_of_agents <= 0 ) CYCLE
2368	ghsa(ghsa_count+1:ghsa_count+number_of_agents) &
2369	= grid_agents(jp,ip)%agents(1:number_of_agents)
2370	ghsa_count = ghsa_count + number_of_agents
2371
2372	ENDDO
2373	ENDDO
2374	ENDIF
2375	IF ( ghsa_count == 0 ) ghsa_count = 1
2376	!
2377	!-- Get all agents that will be sent north into one array
2378	ghna_count = 0
2379	IF ( nyn /= ny ) THEN
2380	DO ip = nxlg, nxrg
2381	DO jp = nyn-2, nyn
2382
2383	number_of_agents = agt_count(jp,ip)
2384	IF ( number_of_agents <= 0 ) CYCLE
2385	ghna(ghna_count+1:ghna_count+number_of_agents) &
2386	= grid_agents(jp,ip)%agents(1:number_of_agents)
2387	ghna_count = ghna_count + number_of_agents
2388
2389	ENDDO
2390	ENDDO
2391	ENDIF
2392	IF ( ghna_count == 0 ) ghna_count = 1
2393	!
2394	!-- Send/receive number of agents that
2395	!-- will be transferred to/from south/north neighbor
2396	CALL MPI_SENDRECV( ghsa_count, 1, MPI_INTEGER, psouth, 0, &
2397	ghna_count_recv, 1, MPI_INTEGER, pnorth, 0, &
2398	comm2d, status, ierr )
2399	ALLOCATE ( agt_gh_n(1:ghna_count_recv) )
2400	!
2401	!-- Send/receive number of agents that
2402	!-- will be transferred to/from north/south neighbor
2403	CALL MPI_SENDRECV( ghna_count, 1, MPI_INTEGER, pnorth, 0, &
2404	ghsa_count_recv, 1, MPI_INTEGER, psouth, 0, &
2405	comm2d, status, ierr )
2406	!
2407	!-- Send/receive flag that indicates if there are actually any agents
2408	!-- in ghost layer
2409	CALL MPI_SENDRECV( ghsa_empty, 1, MPI_LOGICAL, psouth, 1, &
2410	ghna_empty_rcv, 1, MPI_LOGICAL, pnorth, 1, &
2411	comm2d, status, ierr )
2412	CALL MPI_SENDRECV( ghna_empty, 1, MPI_LOGICAL, pnorth, 1, &
2413	ghsa_empty_rcv, 1, MPI_LOGICAL, psouth, 1, &
2414	comm2d, status, ierr )
2415
2416
2417	ALLOCATE ( agt_gh_s(1:ghsa_count_recv) )
2418	!
2419	!-- Get bit size of one agent
2420	agt_size = STORAGE_SIZE(zero_agent)/8
2421	!
2422	!-- Send/receive agents to/from south/north neighbor
2423	CALL MPI_SENDRECV( ghsa, ghsa_count * agt_size, MPI_BYTE, &
2424	psouth,1, &
2425	agt_gh_n, ghna_count_recv * agt_size, MPI_BYTE, &
2426	pnorth,1, &
2427	comm2d, status, ierr )
2428	!
2429	!-- Send/receive agents to/from south/north neighbor
2430	CALL MPI_SENDRECV( ghna, ghna_count * agt_size, MPI_BYTE, &
2431	pnorth,1, &
2432	agt_gh_s, ghsa_count_recv * agt_size, MPI_BYTE, &
2433	psouth,1, &
2434	comm2d, status, ierr )
2435	!
2436	!-- If agents were received, add them to the respective ghost layer cells
2437	IF ( .NOT. ghna_empty_rcv ) THEN
2438	CALL mas_eh_add_ghost_agents_to_gridcell(agt_gh_n)
2439	ENDIF
2440
2441	IF ( .NOT. ghsa_empty_rcv ) THEN
2442	CALL mas_eh_add_ghost_agents_to_gridcell(agt_gh_s)
2443	ENDIF
2444
2445	DEALLOCATE( ghna, ghsa, agt_gh_n, agt_gh_s )
2446
2447	ENDIF
2448
2449	END SUBROUTINE mas_eh_ghost_exchange
2450
2451	!------------------------------------------------------------------------------!
2452	! Description:
2453	! ------------
2454	!> If an agent moves from one grid cell to another (on the current
2455	!> processor!), this subroutine moves the corresponding element from the
2456	!> agent array of the old grid cell to the agent array of the new grid
2457	!> cell.
2458	!------------------------------------------------------------------------------!
2459	SUBROUTINE mas_eh_move_agent
2460
2461	IMPLICIT NONE
2462
2463	INTEGER(iwp) :: i !< grid index (x) of agent position
2464	INTEGER(iwp) :: ip !< index variable along x
2465	INTEGER(iwp) :: j !< grid index (y) of agent position
2466	INTEGER(iwp) :: jp !< index variable along y
2467	INTEGER(iwp) :: n !< index variable for agent array
2468	INTEGER(iwp) :: na_before_move !< number of agents per grid box before moving
2469	INTEGER(iwp) :: aindex !< dummy argument for number of new agent per grid box
2470
2471	TYPE(agent_type), DIMENSION(:), POINTER :: agents_before_move !< agents before moving
2472
2473	CALL cpu_log( log_point_s(19), 'mas_eh_move_agent', 'start' )
2474
2475	DO ip = nxl, nxr
2476	DO jp = nys, nyn
2477
2478	na_before_move = agt_count(jp,ip)
2479	IF ( na_before_move <= 0 ) CYCLE
2480	agents_before_move => grid_agents(jp,ip)%agents(1:na_before_move)
2481
2482	DO n = 1, na_before_move
2483	i = agents_before_move(n)%x * ddx
2484	j = agents_before_move(n)%y * ddy
2485
2486	!-- For mas_eh_exchange_horiz to work properly agents need to be
2487	!-- moved to the outermost gridboxes of the respective processor.
2488	!-- If the agent index is inside the processor the following
2489	!-- lines will not change the index
2490	i = MIN ( i , nxr )
2491	i = MAX ( i , nxl )
2492	j = MIN ( j , nyn )
2493	j = MAX ( j , nys )
2494
2495	!
2496	!-- Check if agent has moved to another grid cell.
2497	IF ( i /= ip .OR. j /= jp ) THEN
2498	!
2499	!-- If the agent stays on the same processor, the agent
2500	!-- will be added to the agent array of the new processor.
2501	number_of_agents = agt_count(j,i)
2502	agents => grid_agents(j,i)%agents(1:number_of_agents)
2503
2504	aindex = number_of_agents+1
2505	IF ( aindex > SIZE(grid_agents(j,i)%agents) ) &
2506	THEN
2507	CALL mas_eh_realloc_agents_array(i,j)
2508	ENDIF
2509
2510	grid_agents(j,i)%agents(aindex) = agents_before_move(n)
2511	agt_count(j,i) = aindex
2512
2513	agents_before_move(n)%agent_mask = .FALSE.
2514	ENDIF
2515	ENDDO
2516
2517	ENDDO
2518	ENDDO
2519
2520	CALL cpu_log( log_point_s(19), 'mas_eh_move_agent', 'stop' )
2521
2522	RETURN
2523
2524	END SUBROUTINE mas_eh_move_agent
2525
2526	!------------------------------------------------------------------------------!
2527	! Description:
2528	! ------------
2529	!> If the allocated memory for the agent array do not suffice to add arriving
2530	!> agents from neighbour grid cells, this subrouting reallocates the
2531	!> agent array to assure enough memory is available.
2532	!------------------------------------------------------------------------------!
2533	SUBROUTINE mas_eh_realloc_agents_array (i,j,size_in)
2534
2535	IMPLICIT NONE
2536
2537	INTEGER(iwp) :: old_size !< old array size
2538	INTEGER(iwp) :: new_size !< new array size
2539
2540	INTEGER(iwp), INTENT(in) :: i !< grid index (y)
2541	INTEGER(iwp), INTENT(in) :: j !< grid index (y)
2542
2543	INTEGER(iwp), INTENT(in), OPTIONAL :: size_in !< size of input array
2544
2545	TYPE(agent_type), DIMENSION(10) :: tmp_agents_s !< temporary static agent array
2546
2547	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: tmp_agents_d !< temporary dynamic agent array
2548
2549	old_size = SIZE(grid_agents(j,i)%agents)
2550
2551	IF ( PRESENT(size_in) ) THEN
2552	new_size = size_in
2553	ELSE
2554	new_size = old_size * ( 1.0_wp + alloc_factor_mas / 100.0_wp )
2555	ENDIF
2556
2557	new_size = MAX( new_size, min_nr_agent, old_size + 1 )
2558
2559	IF ( old_size <= 10 ) THEN
2560
2561	tmp_agents_s(1:old_size) = grid_agents(j,i)%agents(1:old_size)
2562
2563	DEALLOCATE(grid_agents(j,i)%agents)
2564	ALLOCATE(grid_agents(j,i)%agents(new_size))
2565
2566	grid_agents(j,i)%agents(1:old_size) = tmp_agents_s(1:old_size)
2567	grid_agents(j,i)%agents(old_size+1:new_size) = zero_agent
2568
2569	ELSE
2570
2571	ALLOCATE(tmp_agents_d(new_size))
2572	tmp_agents_d(1:old_size) = grid_agents(j,i)%agents
2573
2574	DEALLOCATE(grid_agents(j,i)%agents)
2575	ALLOCATE(grid_agents(j,i)%agents(new_size))
2576
2577	grid_agents(j,i)%agents(1:old_size) = tmp_agents_d(1:old_size)
2578	grid_agents(j,i)%agents(old_size+1:new_size) = zero_agent
2579
2580	DEALLOCATE(tmp_agents_d)
2581
2582	ENDIF
2583	agents => grid_agents(j,i)%agents(1:number_of_agents)
2584
2585	RETURN
2586	END SUBROUTINE mas_eh_realloc_agents_array
2587
2588	!------------------------------------------------------------------------------!
2589	! Description:
2590	! ------------
2591	!> Inquires prognostic model quantities at the position of each agent and
2592	!> stores them in that agent for later output
2593	!------------------------------------------------------------------------------!
2594	SUBROUTINE mas_get_prognostic_quantities
2595
2596	USE arrays_3d, &
2597	ONLY: u, v, pt, hyp
2598
2599	USE chem_gasphase_mod, &
2600	ONLY: nvar
2601
2602	USE chemistry_model_mod, &
2603	ONLY: chem_species
2604
2605	USE control_parameters, &
2606	ONLY: air_chemistry
2607
2608	IMPLICIT NONE
2609
2610	INTEGER(iwp) :: i_offset !< index offset for windspeed measurement
2611	INTEGER(iwp) :: il !< x-index
2612	INTEGER(iwp) :: is !< subgrid box counter
2613	INTEGER(iwp) :: j_offset !< index offset for windspeed measurement
2614	INTEGER(iwp) :: jl !< y-index
2615	INTEGER(iwp) :: kl !< z-index
2616	INTEGER(iwp) :: nl !< agent counter
2617	INTEGER(iwp) :: se !< subgrid box end index
2618	INTEGER(iwp) :: si !< subgrid box start index
2619
2620	REAL(wp) :: u_a !< windspeed at agent position (x)
2621	REAL(wp) :: v_a !< windspeed at agent position (y)
2622	REAL(wp) :: x_a !< agent position (x)
2623	REAL(wp) :: y_a !< agent position (y)
2624
2625	DO il = nxl, nxr
2626	DO jl = nys, nyn
2627
2628	number_of_agents = agt_count(jl,il)
2629	!
2630	!-- If grid cell is empty, cycle
2631	IF ( number_of_agents <= 0 ) CYCLE
2632	kl = s_measure_height(jl,il)
2633
2634	agents => grid_agents(jl,il)%agents(1:number_of_agents)
2635	!
2636	!-- loop over the four subgrid boxes
2637	DO is = 0,3
2638	!
2639	!-- Set indices
2640	si = grid_agents(jl,il)%start_index(is)
2641	se = grid_agents(jl,il)%end_index(is)
2642	DO nl = si, se
2643	!
2644	!-- Calculate index offset in x-direction:
2645	!-- Left value if wall right of grid box
2646	!-- Right value if wall left of grid box
2647	!-- Else the one that is closer to the agent
2648	IF ( BTEST( obstacle_flags( jl, il+1 ), 6 ) ) THEN
2649	i_offset = 0
2650	ELSEIF ( BTEST( obstacle_flags( jl, il-1 ), 2 ) ) THEN
2651	i_offset = 1
2652	ELSE
2653	i_offset = MERGE( 0, 1, BTEST(is,1) )
2654	ENDIF
2655	u_a = u( kl, jl, il + i_offset )
2656	!
2657	!-- Calculate index offset in y-direction:
2658	!-- South value if wall north of grid box
2659	!-- North value if wall south of grid box
2660	!-- Else the one that is closer to the agent
2661	IF ( BTEST( obstacle_flags( jl+1, il ), 4 ) ) THEN
2662	j_offset = 0
2663	ELSEIF ( BTEST( obstacle_flags( jl-1, il ), 0 ) ) THEN
2664	j_offset = 1
2665	ELSE
2666	j_offset = MERGE( 0, 1, BTEST(is,0) )
2667	ENDIF
2668	v_a = v( kl, jl + j_offset, il )
2669	!
2670	!-- Calculate windspeed at agent postion
2671	agents(nl)%windspeed = SQRT(u_a2 + v_a2)
2672	!
2673	!-- Calculate temperature at agent position
2674	agents(nl)%t = pt(kl,jl,il) * &
2675	( hyp(kl) / 100000.0_wp )**0.286_wp
2676	! !
2677	! !-- Get PM10 concentration at agent position, if possible
2678	! IF ( ind_pm10 == -9 ) THEN
2679	! agents(nl)%pm10 = 0.0_wp
2680	! ELSE
2681	! agents(nl)%pm10 = chem_species(ind_pm10)%conc(kl,jl,il)
2682	! ENDIF
2683	! !
2684	! !-- Get PM10 concentration at agent position, if possible
2685	! IF ( ind_pm25 == -9 ) THEN
2686	! agents(nl)%pm25 = 0.0_wp
2687	! ELSE
2688	! agents(nl)%pm25 = chem_species(ind_pm25)%conc(kl,jl,il)
2689	! ENDIF
2690	ENDDO
2691
2692	ENDDO
2693
2694	ENDDO
2695	ENDDO
2696
2697	END SUBROUTINE mas_get_prognostic_quantities
2698
2699	!------------------------------------------------------------------------------!
2700	! Description:
2701	! ------------
2702	!> Adds an item to the priority queue (binary heap) at the correct position
2703	!------------------------------------------------------------------------------!
2704	SUBROUTINE mas_heap_insert_item( id, priority )
2705
2706	IMPLICIT NONE
2707
2708	INTEGER(iwp) :: cur_pos !< current position
2709	INTEGER(iwp) :: id !< mesh ID of item
2710
2711	REAL(wp) :: priority !< item priority
2712
2713	TYPE(heap_item) :: item !< heap item
2714
2715	item%mesh_id = id
2716	item%priority = priority
2717	!
2718	!-- Extend heap, if necessary
2719	IF ( heap_count + 1 > SIZE(queue) ) THEN
2720	CALL mas_heap_extend
2721	ENDIF
2722	!
2723	!-- Insert item at first unoccupied postion (highest index) of heap
2724	cur_pos = heap_count
2725	queue(cur_pos) = item
2726	!
2727	!-- Sort while inserted item is not at top of heap
2728	DO WHILE ( cur_pos /= 0 )
2729	!
2730	!-- If priority < its parent's priority, swap them.
2731	!-- Else, sorting is done.
2732	IF ( queue(cur_pos)%priority &
2733	< queue(FLOOR((cur_pos)/2.))%priority ) &
2734	THEN
2735	item = queue(cur_pos)
2736	queue(cur_pos) = queue(FLOOR((cur_pos)/2.))
2737	queue(FLOOR((cur_pos)/2.)) = item
2738	cur_pos = FLOOR((cur_pos)/2.)
2739	ELSE
2740	EXIT
2741	ENDIF
2742	ENDDO
2743	!
2744	!-- Item was added to heap, so the heap count increases
2745	heap_count = heap_count + 1
2746
2747	END SUBROUTINE mas_heap_insert_item
2748
2749	!------------------------------------------------------------------------------!
2750	! Description:
2751	! ------------
2752	!> Extends the size of the priority queue (binary heap)
2753	!------------------------------------------------------------------------------!
2754	SUBROUTINE mas_heap_extend
2755
2756	IMPLICIT NONE
2757
2758	INTEGER(iwp) :: soh !< size of heap
2759
2760	TYPE(heap_item), DIMENSION(:), ALLOCATABLE :: dummy_heap !< dummy heap
2761
2762	soh = SIZE(queue)-1
2763	ALLOCATE(dummy_heap(0:soh))
2764	dummy_heap = queue
2765	DEALLOCATE(queue)
2766	ALLOCATE(queue(0:2*soh+1))
2767	queue(0:soh) = dummy_heap(0:soh)
2768
2769	END SUBROUTINE mas_heap_extend
2770
2771	!------------------------------------------------------------------------------!
2772	! Description:
2773	! ------------
2774	!> Removes first (smallest) element from the priority queue, reorders the rest
2775	!> and returns the ID of the removed mesh point
2776	!------------------------------------------------------------------------------!
2777	SUBROUTINE mas_heap_extract_item ( id )
2778
2779	IMPLICIT NONE
2780
2781	INTEGER(iwp) :: id !< ID of item extracted item
2782	INTEGER(iwp) :: child !< child of item in heap
2783	INTEGER(iwp) :: cur_pos !< current position of item in heap
2784
2785	TYPE(heap_item) :: dummy
2786	!
2787	!-- Get ID of mesh point with lowest priority (extracted item: top of heap)
2788	id = queue(0)%mesh_id
2789	!
2790	!-- Put last item in heap at first position
2791	queue(0) = queue(heap_count-1)
2792	cur_pos = 0
2793	DO
2794	!
2795	!-- If current item has no children, sorting is done
2796	IF( 2*cur_pos+1 > heap_count - 1 ) THEN
2797	EXIT
2798	!
2799	!-- If current item has only one child, check if item and its child are
2800	!-- ordered correctly. Else, swap them.
2801	ELSEIF ( 2*cur_pos+2 > heap_count - 1 ) THEN
2802	IF ( queue(cur_pos)%priority > queue(2*cur_pos+1)%priority ) THEN
2803	dummy = queue(cur_pos)
2804	queue(cur_pos) = queue(2*cur_pos+1)
2805	queue(2*cur_pos+1) = dummy
2806	cur_pos = 2*cur_pos+1
2807	ELSE
2808	EXIT
2809	ENDIF
2810	ELSE
2811	!
2812	!-- determine the smaller child
2813	IF ( queue(2*cur_pos+1)%priority &
2814	>= queue(2*cur_pos+2)%priority ) &
2815	THEN
2816	child = 2
2817	ELSE
2818	child = 1
2819	ENDIF
2820	!
2821	!-- Check if item and its smaller child are ordered falsely. If so,
2822	!-- swap them. Else, sorting is done.
2823	IF ( queue(cur_pos)%priority > queue(2*cur_pos+child )%priority ) &
2824	THEN
2825	dummy = queue(cur_pos)
2826	queue(cur_pos) = queue(2*cur_pos+child)
2827	queue(2*cur_pos+child) = dummy
2828	cur_pos = 2*cur_pos+child
2829	ELSE
2830	EXIT
2831	ENDIF
2832	ENDIF
2833	ENDDO
2834	!
2835	!-- Top item was removed from heap, thus, heap_cout decreases by one
2836	heap_count = heap_count-1
2837
2838	END SUBROUTINE mas_heap_extract_item
2839
2840	!------------------------------------------------------------------------------!
2841	! Description:
2842	! ------------
2843	!> Initialization of Multi Agent System
2844	!------------------------------------------------------------------------------!
2845	SUBROUTINE mas_init
2846
2847	USE chem_gasphase_mod, &
2848	ONLY: nspec
2849
2850	USE chemistry_model_mod, &
2851	ONLY: chem_species
2852
2853	USE control_parameters, &
2854	ONLY: air_chemistry, coupling_char, initializing_actions, &
2855	io_blocks, io_group
2856
2857	USE surface_mod, &
2858	ONLY: get_topography_top_index, get_topography_top_index_ji
2859
2860	USE arrays_3d, &
2861	ONLY: zu, zw
2862
2863	USE indices, &
2864	ONLY: nzt
2865
2866	IMPLICIT NONE
2867
2868	INTEGER(iwp) :: i !< grid cell (x)
2869	INTEGER(iwp) :: ii !< io-block counter
2870	INTEGER(iwp) :: il !< io-block counter
2871	INTEGER(iwp) :: jl !< io-block counter
2872	INTEGER(iwp) :: kl !< io-block counter
2873	INTEGER(iwp) :: kdum !< io-block counter
2874	INTEGER(iwp) :: locdum !< io-block counter
2875	INTEGER(iwp) :: j !< grid cell (y)
2876	INTEGER(iwp) :: size_of_mesh !< temporary value for read
2877	INTEGER(iwp) :: size_of_pols !< temporary value for read
2878	INTEGER(iwp) :: ioerr !< IOSTAT flag for IO-commands ( 0 = no error )
2879
2880	REAL(wp) :: zdum !< dummy for measurement height
2881	REAL(wp) :: avg_agt_height = 1.8_wp
2882
2883	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: noc !< temp: number of connections in nav_mesh
2884
2885	!
2886	!-- Check the number of agent groups.
2887	IF ( number_of_agent_groups > max_number_of_agent_groups ) THEN
2888	WRITE( message_string, * ) 'max_number_of_agent_groups =', &
2889	max_number_of_agent_groups , &
2890	'&number_of_agent_groups reset to ', &
2891	max_number_of_agent_groups
2892	CALL message( 'mas_init', 'PA0072', 0, 1, 0, 6, 0 )
2893	number_of_agent_groups = max_number_of_agent_groups
2894	ENDIF
2895
2896	!
2897	!-- Set some parameters
2898	d_sigma_rep_agent = 1.0_wp/sigma_rep_agent
2899	d_sigma_rep_wall = 1.0_wp/sigma_rep_wall
2900	d_tau_accel_agent = 1.0_wp/tau_accel_agent
2901	IF ( dt_agent /= 999.0_wp ) THEN
2902	agent_own_timestep = .TRUE.
2903	ENDIF
2904
2905	!
2906	!-- Get index of first grid box above topography
2907	ALLOCATE( top_top_s(nysg:nyng,nxlg:nxrg), &
2908	top_top_w(nysg:nyng,nxlg:nxrg), &
2909	s_measure_height(nys:nyn,nxl:nxr) )
2910	!
2911	!-- Get first index above topography for scalar grid and last index in
2912	!-- topography for z-component of wind
2913	DO il = nxlg, nxrg
2914	DO jl = nysg, nyng
2915	top_top_s(jl,il) = get_topography_top_index_ji(jl,il,'s') + 1
2916	top_top_w(jl,il) = get_topography_top_index_ji(jl,il,'w')
2917	ENDDO
2918	ENDDO
2919	!
2920	!-- Create 2D array containing the index at which measurements are done by
2921	!-- agents. The height of this measurement is given by avg_agt_height.
2922	DO il = nxl, nxr
2923	DO jl = nys, nyn
2924
2925	kdum = top_top_w(jl,il)
2926	zdum = zw(kdum)
2927	zdum = zdum + avg_agt_height
2928	locdum = 0
2929	!
2930	!-- Locate minimum distance from u-grid to measurement height (zdum)
2931	DO kl = 1, nzt
2932	IF ( ABS(zu(kl)-zdum) < ABS(zu(locdum)-zdum) ) locdum = kl
2933	ENDDO
2934	s_measure_height(jl,il) = locdum
2935
2936	ENDDO
2937	ENDDO
2938	! !
2939	! !-- Get indices of PM10 and PM2.5 species, if active
2940	! IF ( air_chemistry ) THEN
2941	! DO il = 1, nspec
2942	! print*,chem_species(il)%name
2943	! ! IF ( spec_name(1:4) == 'PM10' ) THEN
2944	! ! ind_pm10 = il
2945	! ! ELSEIF ( spec_name(1:4) == 'PM25' ) THEN
2946	! ! ind_pm25 = il
2947	! ! ENDIF
2948	!
2949	! ENDDO
2950	! ENDIF
2951	! stop
2952	CALL mas_create_obstacle_flags
2953
2954	!
2955	!-- Set default start positions, if necessary
2956	IF ( asl(1) == 9999999.9_wp ) asl(1) = 0.0_wp
2957	IF ( asr(1) == 9999999.9_wp ) asr(1) = ( nx + 1 ) * dx
2958	IF ( ass(1) == 9999999.9_wp ) ass(1) = 0.0_wp
2959	IF ( asn(1) == 9999999.9_wp ) asn(1) = ( ny + 1 ) * dy
2960	IF ( adx(1) == 9999999.9_wp .OR. adx(1) == 0.0_wp ) adx(1) = dx
2961	IF ( ady(1) == 9999999.9_wp .OR. ady(1) == 0.0_wp ) ady(1) = dy
2962
2963	DO j = 2, number_of_agent_groups
2964	IF ( asl(j) == 9999999.9_wp ) asl(j) = asl(j-1)
2965	IF ( asr(j) == 9999999.9_wp ) asr(j) = asr(j-1)
2966	IF ( ass(j) == 9999999.9_wp ) ass(j) = ass(j-1)
2967	IF ( asn(j) == 9999999.9_wp ) asn(j) = asn(j-1)
2968	IF ( adx(j) == 9999999.9_wp .OR. adx(j) == 0.0_wp ) adx(j) = adx(j-1)
2969	IF ( ady(j) == 9999999.9_wp .OR. ady(j) == 0.0_wp ) ady(j) = ady(j-1)
2970	ENDDO
2971
2972	!
2973	!-- Check boundary condition and set internal variables
2974	SELECT CASE ( bc_mas_lr )
2975
2976	CASE ( 'cyclic' )
2977	ibc_mas_lr = 0
2978
2979	CASE ( 'absorb' )
2980	ibc_mas_lr = 1
2981
2982	CASE DEFAULT
2983	WRITE( message_string, * ) 'unknown boundary condition ', &
2984	'bc_mas_lr = "', TRIM( bc_mas_lr ), '"'
2985	CALL message( 'mas_init', 'PA0073', 1, 2, 0, 6, 0 )
2986
2987	END SELECT
2988	SELECT CASE ( bc_mas_ns )
2989
2990	CASE ( 'cyclic' )
2991	ibc_mas_ns = 0
2992
2993	CASE ( 'absorb' )
2994	ibc_mas_ns = 1
2995
2996	CASE DEFAULT
2997	WRITE( message_string, * ) 'unknown boundary condition ', &
2998	'bc_mas_ns = "', TRIM( bc_mas_ns ), '"'
2999	CALL message( 'mas_init', 'PA0074', 1, 2, 0, 6, 0 )
3000
3001	END SELECT
3002
3003	!
3004	!-- For the first model run of a possible job chain initialize the
3005	!-- agents, otherwise read the agent data from restart file.
3006	IF ( TRIM( initializing_actions ) == 'read_restart_data' &
3007	.AND. read_agents_from_restartfile ) THEN
3008
3009	! CALL mas_read_restart_file
3010
3011	ELSE
3012	!
3013	!-- Read preprocessed data of navigation mesh and building polygons
3014	!-- for agent pathfinding
3015	DO ii = 0, io_blocks-1
3016	IF ( ii == io_group ) THEN
3017	OPEN ( 119, FILE='NAVIGATION_DATA'//TRIM( coupling_char ), &
3018	FORM='UNFORMATTED', IOSTAT=ioerr )
3019	!
3020	!-- Read mesh data
3021	READ(119) size_of_mesh
3022	ALLOCATE( mesh(1:size_of_mesh))
3023	DO i = 1, size_of_mesh
3024	READ(119) mesh(i)%polygon_id, mesh(i)%vertex_id, &
3025	mesh(i)%noc, mesh(i)%origin_id, &
3026	mesh(i)%cost_so_far, mesh(i)%x, &
3027	mesh(i)%y, mesh(i)%x_s, mesh(i)%y_s
3028	ALLOCATE( mesh(i)%connected_vertices(1:mesh(i)%noc), &
3029	mesh(i)%distance_to_vertex(1:mesh(i)%noc) )
3030	DO j = 1, mesh(i)%noc
3031	READ(119) mesh(i)%connected_vertices(j), &
3032	mesh(i)%distance_to_vertex(j)
3033	ENDDO
3034	ENDDO
3035	!
3036	!-- Read polygon data
3037	READ(119) size_of_pols
3038	ALLOCATE( polygons(1:size_of_pols) )
3039	DO i = 1, size_of_pols
3040	READ(119) polygons(i)%nov
3041	ALLOCATE( polygons(i)%vertices(0:polygons(i)%nov+1) )
3042	DO j = 0, polygons(i)%nov+1
3043	READ(119) polygons(i)%vertices(j)%delete, &
3044	polygons(i)%vertices(j)%x, &
3045	polygons(i)%vertices(j)%y
3046	ENDDO
3047	ENDDO
3048	CLOSE(119)
3049
3050	ENDIF
3051	#if defined( __parallel ) && ! defined ( __check )
3052	CALL MPI_BARRIER( comm2d, ierr )
3053	#endif
3054	ENDDO
3055
3056	!
3057	!-- Allocate agent arrays and set attributes of the initial set of
3058	!-- agents, which can be also periodically released at later times.
3059	ALLOCATE( agt_count (nysg:nyng,nxlg:nxrg), &
3060	grid_agents(nysg:nyng,nxlg:nxrg) )
3061
3062	number_of_agents = 0
3063	sort_count_mas = 0
3064	agt_count = 0
3065
3066	!
3067	!-- initialize counter for agent IDs
3068	grid_agents%id_counter = 1
3069
3070	!
3071	!-- Initialize all agents with dummy values (otherwise errors may
3072	!-- occur within restart runs). The reason for this is still not clear
3073	!-- and may be presumably caused by errors in the respective user-interface.
3074	zero_agent%agent_mask = .FALSE.
3075	zero_agent%block_nr = -1
3076	zero_agent%group = 0
3077	zero_agent%id = 0_idp
3078	zero_agent%path_counter = SIZE(zero_agent%path_x)
3079	zero_agent%age = 0.0_wp
3080	zero_agent%age_m = 0.0_wp
3081	zero_agent%dt_sum = 0.0_wp
3082	zero_agent%clo = 0.0_wp
3083	zero_agent%energy_storage= 0.0_wp
3084	zero_agent%force_x = 0.0_wp
3085	zero_agent%force_y = 0.0_wp
3086	zero_agent%origin_x = 0.0_wp
3087	zero_agent%origin_y = 0.0_wp
3088	zero_agent%speed_abs = 0.0_wp
3089	zero_agent%speed_e_x = 0.0_wp
3090	zero_agent%speed_e_y = 0.0_wp
3091	zero_agent%speed_des = random_normal(desired_speed, des_sp_sig)
3092	zero_agent%speed_x = 0.0_wp
3093	zero_agent%speed_y = 0.0_wp
3094	zero_agent%thermal_index = 0.0_wp
3095	zero_agent%x = 0.0_wp
3096	zero_agent%y = 0.0_wp
3097	zero_agent%path_x = 0.0_wp
3098	zero_agent%path_y = 0.0_wp
3099	zero_agent%t_x = 0.0_wp
3100	zero_agent%t_y = 0.0_wp
3101
3102	!
3103	!-- Set a seed value for the random number generator to be exclusively
3104	!-- used for the agent code. The generated random numbers should be
3105	!-- different on the different PEs.
3106	iran_agent = iran_agent + myid
3107
3108	CALL mas_create_agent (PHASE_INIT)
3109
3110	ENDIF
3111
3112	!
3113	!-- To avoid programm abort, assign agents array to the local version of
3114	!-- first grid cell
3115	number_of_agents = agt_count(nys,nxl)
3116	agents => grid_agents(nys,nxl)%agents(1:number_of_agents)
3117
3118	END SUBROUTINE mas_init
3119
3120	!------------------------------------------------------------------------------!
3121	! Description:
3122	! ------------
3123	!> Adds a connection between two points of the navigation mesh
3124	!> (one-way: in_mp1 to in_mp2)
3125	!------------------------------------------------------------------------------!
3126	SUBROUTINE mas_nav_add_connection ( in_mp1, id2, in_mp2 )
3127
3128	IMPLICIT NONE
3129
3130	LOGICAL :: connection_established !< Flag to indicate if connection has already been established
3131
3132	INTEGER(iwp) :: id2 !< ID of in_mp2
3133	INTEGER(iwp) :: il !< local counter
3134	INTEGER(iwp) :: noc1 !< number of connections in in_mp1
3135
3136	INTEGER, DIMENSION(:), ALLOCATABLE :: dum_cv !< dummy array for connected_vertices
3137
3138	REAL(wp) :: dist !< Distance between the two points
3139
3140	REAL(wp), DIMENSION(:), ALLOCATABLE :: dum_dtv
3141
3142	TYPE(mesh_point) :: in_mp1 !< mesh point that gets a new connection
3143	TYPE(mesh_point) :: in_mp2 !< mesh point in_mp1 will be connected to
3144
3145	connection_established = .FALSE.
3146	!
3147	!-- Check if connection has already been established
3148	noc1 = SIZE(in_mp1%connected_vertices)
3149	DO il = 1, in_mp1%noc
3150	IF ( in_mp1%connected_vertices(il) == id2 ) THEN
3151	connection_established = .TRUE.
3152	EXIT
3153	ENDIF
3154	ENDDO
3155
3156	IF ( .NOT. connection_established ) THEN
3157	!
3158	!-- Resize arrays, if necessary
3159	IF ( in_mp1%noc >= noc1 ) THEN
3160	ALLOCATE( dum_cv(1:noc1),dum_dtv(1:noc1) )
3161	dum_cv = in_mp1%connected_vertices
3162	dum_dtv = in_mp1%distance_to_vertex
3163	DEALLOCATE( in_mp1%connected_vertices, in_mp1%distance_to_vertex )
3164	ALLOCATE( in_mp1%connected_vertices(1:2*noc1), &
3165	in_mp1%distance_to_vertex(1:2*noc1) )
3166	in_mp1%connected_vertices = -999
3167	in_mp1%distance_to_vertex = -999.
3168	in_mp1%connected_vertices(1:noc1) = dum_cv
3169	in_mp1%distance_to_vertex(1:noc1) = dum_dtv
3170	ENDIF
3171
3172	!
3173	!-- Add connection
3174	in_mp1%noc = in_mp1%noc+1
3175	dist = SQRT( (in_mp1%x - in_mp2%x)2 + (in_mp1%y - in_mp2%y)2 )
3176	in_mp1%connected_vertices(in_mp1%noc) = id2
3177	in_mp1%distance_to_vertex(in_mp1%noc) = dist
3178	ENDIF
3179
3180	END SUBROUTINE mas_nav_add_connection
3181
3182	!------------------------------------------------------------------------------!
3183	! Description:
3184	! ------------
3185	!> Adds a vertex (curren position of agent or target) to the existing tmp_mesh
3186	!------------------------------------------------------------------------------!
3187	SUBROUTINE mas_nav_add_vertex_to_mesh ( in_mp, in_id )
3188
3189	IMPLICIT NONE
3190
3191	LOGICAL :: intersection_found !< flag
3192
3193	INTEGER(iwp) :: jl !< mesh point counter
3194	INTEGER(iwp) :: pl !< polygon counter
3195	INTEGER(iwp) :: vl !< vertex counter
3196	INTEGER(iwp) :: pid_t !< polygon id of tested mesh point
3197	INTEGER(iwp) :: vid_t !< vertex id of tested mesh point
3198	INTEGER(iwp) :: in_id !< vertex id of tested mesh point
3199
3200	REAL(wp) :: v1x !< x-coordinate of test vertex 1 for intersection test
3201	REAL(wp) :: v1y !< y-coordinate of test vertex 1 for intersection test
3202	REAL(wp) :: v2x !< x-coordinate of test vertex 2 for intersection test
3203	REAL(wp) :: v2y !< y-coordinate of test vertex 2 for intersection test
3204	REAL(wp) :: x !< x-coordinate of current mesh point
3205	REAL(wp) :: x_t !< x-coordinate of tested mesh point
3206	REAL(wp) :: y !< y-coordinate of current mesh point
3207	REAL(wp) :: y_t !< y-coordinate of tested mesh point
3208
3209	TYPE(mesh_point) :: in_mp !< Input mesh point
3210	!
3211	!--
3212	x = in_mp%x
3213	y = in_mp%y
3214	DO jl = 0, SIZE(tmp_mesh)-2
3215	IF ( in_id == jl ) CYCLE
3216	!
3217	!-- Ignore mesh points with 0 connections
3218	IF ( tmp_mesh(jl)%polygon_id /= -1 ) THEN
3219	IF ( tmp_mesh(jl)%noc == 0 ) CYCLE
3220	ENDIF
3221	x_t = tmp_mesh(jl)%x
3222	y_t = tmp_mesh(jl)%y
3223	pid_t = tmp_mesh(jl)%polygon_id
3224	vid_t = tmp_mesh(jl)%vertex_id
3225	!
3226	!-- If the connecting line between the target and a mesh point points
3227	!-- into the mesh point's polygon, no connection will be
3228	!-- established between the two points. This is the case if the
3229	!-- previous (next) vertex of the polygon is right of the connecting
3230	!-- line and the next (previous) vertex of the polygon is left of the
3231	!-- connecting line.
3232	IF ( pid_t > 0 .AND. pid_t <= SIZE(polygons) ) THEN
3233	IF ( (((is_left(x,y,x_t,y_t,polygons(pid_t)%vertices(vid_t-1)%x, &
3234	polygons(pid_t)%vertices(vid_t-1)%y) &
3235	.AND. is_right(x,y,x_t,y_t, &
3236	polygons(pid_t)%vertices(vid_t+1)%x, &
3237	polygons(pid_t)%vertices(vid_t+1)%y) ) &
3238	.OR. (is_right(x,y,x_t,y_t, &
3239	polygons(pid_t)%vertices(vid_t-1)%x, &
3240	polygons(pid_t)%vertices(vid_t-1)%y) &
3241	.AND. is_left(x,y,x_t,y_t, &
3242	polygons(pid_t)%vertices(vid_t+1)%x, &
3243	polygons(pid_t)%vertices(vid_t+1)%y)))))&
3244	THEN
3245	CYCLE
3246	ENDIF
3247	ENDIF
3248	!
3249	!-- For each edge of each polygon, check if it intersects with the
3250	!-- potential connection. If at least one intersection is found,
3251	!-- no connection can be made
3252	intersection_found = .FALSE.
3253	DO pl = 1, SIZE(polygons)
3254	DO vl = 1, polygons(pl)%nov
3255	v1x = polygons(pl)%vertices(vl)%x
3256	v1y = polygons(pl)%vertices(vl)%y
3257	v2x = polygons(pl)%vertices(vl+1)%x
3258	v2y = polygons(pl)%vertices(vl+1)%y
3259	intersection_found = intersect(x,y,x_t,y_t,v1x,v1y,v2x,v2y)
3260	IF ( intersection_found ) THEN
3261	EXIT
3262	ENDIF
3263	ENDDO
3264	IF ( intersection_found ) EXIT
3265	ENDDO
3266	IF ( intersection_found ) CYCLE
3267	!
3268	!-- If neither of the above two test was true, a connection will be
3269	!-- established between the two mesh points.
3270	CALL mas_nav_add_connection(in_mp,jl, tmp_mesh(jl))
3271	CALL mas_nav_add_connection(tmp_mesh(jl),in_id, in_mp)
3272	ENDDO
3273	CALL mas_nav_reduce_connections(in_mp)
3274
3275	END SUBROUTINE mas_nav_add_vertex_to_mesh
3276
3277	!------------------------------------------------------------------------------!
3278	! Description:
3279	! ------------
3280	!> Creates a temporary copy of the navigation mesh to be used for pathfinding
3281	!------------------------------------------------------------------------------!
3282	SUBROUTINE mas_nav_create_tmp_mesh( a_x, a_y, t_x, t_y, som )
3283
3284	IMPLICIT NONE
3285
3286	INTEGER(iwp) :: som !< size of mesh
3287	INTEGER(iwp) :: noc !< number of connetions
3288	INTEGER(iwp) :: im !< local mesh point counter
3289
3290	REAL(wp) :: a_x !< x-coordinate agent
3291	REAL(wp) :: a_y !< y-coordinate agent
3292	REAL(wp) :: t_x !< x-coordinate target
3293	REAL(wp) :: t_y !< y-coordinate target
3294	!
3295	!-- give tmp_mesh the size of mesh
3296	som = SIZE(mesh)+1
3297	ALLOCATE(tmp_mesh(0:som))
3298	!
3299	!-- give the allocatable variables in tmp_mesh their respctive sizes
3300	DO im = 1, som-1
3301	noc = mesh(im)%noc
3302	ALLOCATE(tmp_mesh(im)%connected_vertices(1:noc))
3303	ALLOCATE(tmp_mesh(im)%distance_to_vertex(1:noc))
3304	ENDDO
3305	!
3306	!-- copy mesh to tmp_mesh
3307	tmp_mesh(1:som-1) = mesh(1:som-1)
3308	!
3309	!-- Add target point ...
3310	CALL mas_nav_init_mesh_point(tmp_mesh(0),-1_iwp,-1_iwp,t_x, t_y)
3311	CALL mas_nav_add_vertex_to_mesh(tmp_mesh(0),0_iwp)
3312	!
3313	!-- ... and start point to temp mesh
3314	CALL mas_nav_init_mesh_point(tmp_mesh(som),-1_iwp,-1_iwp,a_x, a_y)
3315	CALL mas_nav_add_vertex_to_mesh(tmp_mesh(som),som)
3316
3317	END SUBROUTINE mas_nav_create_tmp_mesh
3318
3319	!------------------------------------------------------------------------------!
3320	! Description:
3321	! ------------
3322	!> Finds the shortest path from agent position to target using A*-algorithm
3323	!------------------------------------------------------------------------------!
3324	SUBROUTINE mas_nav_find_path( i_ag )
3325
3326	IMPLICIT NONE
3327
3328	LOGICAL :: target_reached !< flag
3329
3330	INTEGER(iwp) :: cur_node !< current node of binary heap
3331	INTEGER(iwp) :: i_ag !< agent index
3332	INTEGER(iwp) :: il !< counter (x)
3333	INTEGER(iwp) :: jl !< counter (y)
3334	INTEGER(iwp) :: neigh_node !< neighbor node
3335	INTEGER(iwp) :: node_counter !< binary heap node counter
3336	INTEGER(iwp) :: path_ag !< index of agent path
3337	INTEGER(iwp) :: som !< size of mesh
3338	INTEGER(iwp) :: rn_side !< index of agent path
3339	INTEGER(iwp) :: steps !< steps along the path
3340
3341	REAL(wp) :: a_x !< x-coordinate agent
3342	REAL(wp) :: a_y !< y-coordinate agent
3343	REAL(wp) :: new_cost !< updated cost to reach node
3344	REAL(wp) :: new_priority !< priority of node to be added to queue
3345	REAL(wp) :: rand_nr !< x-coordinate target
3346	REAL(wp) :: rn_gate !< random number for corner gate
3347	REAL(wp) :: t_x !< x-coordinate target
3348	REAL(wp) :: t_y !< y-coordinate target
3349	!
3350	!-- Coordinate Type
3351	TYPE coord
3352	REAL(wp) :: x !< x-coordinate
3353	REAL(wp) :: x_s !< x-coordinate (shifted)
3354	REAL(wp) :: y !< y-coordinate
3355	REAL(wp) :: y_s !< y-coordinate (shifted)
3356	END TYPE coord
3357
3358	TYPE(coord), DIMENSION(:), ALLOCATABLE, TARGET :: path !< path array
3359	TYPE(coord), DIMENSION(:), ALLOCATABLE, TARGET :: tmp_path !< temporary path for resizing
3360
3361	CALL cpu_log( log_point_s(20), 'mas_nav_find_path', 'start' )
3362	node_counter = 0
3363	a_x = agents(i_ag)%x
3364	a_y = agents(i_ag)%y
3365	t_x = agents(i_ag)%t_x
3366	t_y = agents(i_ag)%t_y
3367
3368	!
3369	!-- Create temporary navigation mesh including agent and target positions
3370	CALL mas_nav_create_tmp_mesh( a_x, a_y, t_x, t_y, som )
3371	tmp_mesh(som)%cost_so_far = 0.0_wp
3372	!
3373	!-- Initialize priority queue
3374	heap_count = 0_iwp
3375	ALLOCATE(queue(0:100))
3376	target_reached = .FALSE.
3377	!
3378	!-- Add starting point (agent position) to frontier (the frontier consists
3379	!-- of all the nodes that are to be visited. The node with the smallest
3380	!-- priority will be visited first. The priority consists of the distance
3381	!-- from the start node to this node plus a minimal guess (direct distance)
3382	!-- from this node to the goal). For the starting node, the priority is set
3383	!-- to 0, as it's the only node thus far
3384	CALL mas_heap_insert_item(som,0.0_wp)
3385	cur_node = som
3386	DO WHILE ( heap_count > 0 )
3387	!
3388	!-- Step one: Pick lowest priority item from queue
3389	node_counter = node_counter + 1
3390	CALL mas_heap_extract_item(cur_node)
3391	!
3392	!-- Node 0 is the goal node
3393	IF ( cur_node == 0 ) THEN
3394	EXIT
3395	ENDIF
3396	!
3397	!-- Loop over all of cur_node's neighbors
3398	DO il = 1, tmp_mesh(cur_node)%noc
3399	neigh_node = tmp_mesh(cur_node)%connected_vertices(il)
3400	!
3401	!-- Check, if the way from the start node to this neigh_node via
3402	!-- cur_node is shorter than the previously found shortest path to it.
3403	!-- If so, replace said cost and add neigh_node to the frontier.
3404	!-- cost_so_far is initialized as 1.d12 so that all found distances
3405	!-- should be smaller.
3406	new_cost = tmp_mesh(cur_node)%cost_so_far &
3407	+ tmp_mesh(cur_node)%distance_to_vertex(il)
3408	IF ( new_cost < tmp_mesh(neigh_node)%cost_so_far ) THEN
3409	tmp_mesh(neigh_node)%cost_so_far = new_cost
3410	tmp_mesh(neigh_node)%origin_id = cur_node
3411	!
3412	!-- Priority in the queue is cost_so_far + heuristic to goal
3413	new_priority = new_cost &
3414	+ heuristic(tmp_mesh(neigh_node)%x, &
3415	tmp_mesh(neigh_node)%y, tmp_mesh(0)%x, &
3416	tmp_mesh(0)%y)
3417	CALL mas_heap_insert_item(neigh_node,new_priority)
3418	ENDIF
3419	ENDDO
3420	ENDDO
3421	!
3422	!-- Pathfinding is done. Add nodes to a path array, then give the
3423	!-- first 15 intermittent targets to the agent.
3424	DEALLOCATE(queue)
3425	cur_node = 0
3426	steps = 0
3427	ALLOCATE(path(1:100))
3428	DO WHILE ( cur_node /= -1 )
3429	steps = steps + 1
3430	!
3431	!-- Resize path array if necessary
3432	IF ( steps > SIZE(path) ) THEN
3433	ALLOCATE(tmp_path(1:steps-1))
3434	tmp_path(1:steps-1) = path(1:steps-1)
3435	DEALLOCATE(path)
3436	ALLOCATE(path(1:2*(steps-1)))
3437	path(1:steps-1) = tmp_path(1:steps-1)
3438	DEALLOCATE(tmp_path)
3439	ENDIF
3440	path(steps)%x = tmp_mesh(cur_node)%x
3441	path(steps)%y = tmp_mesh(cur_node)%y
3442	path(steps)%x_s = tmp_mesh(cur_node)%x_s
3443	path(steps)%y_s = tmp_mesh(cur_node)%y_s
3444	cur_node = tmp_mesh(cur_node)%origin_id
3445	ENDDO
3446	!
3447	!-- Add calculated intermittent targets to agent path until either the
3448	!-- target or the maximum number of intermittent targets is reached.
3449	!-- Ignore starting point (reduce index by one), it is agent position.
3450	path_ag = 1
3451	steps = steps - 1
3452	DO WHILE( steps > 0 .AND. path_ag < SIZE(agents(i_ag)%path_x) )
3453	!
3454	!-- Each target point is randomly chosen along a line target along the
3455	!-- bisector of the building corner that starts at corner_gate_start
3456	!-- and has a width of corner_gate_width. This is to avoid clustering
3457	!-- when opposing agent groups try to reach the same corner target.
3458	rn_gate = random_function(iran_agent) * corner_gate_width &
3459	+ corner_gate_start
3460	agents(i_ag)%path_x(path_ag) = path(steps)%x + rn_gate &
3461	* (path(steps)%x_s - path(steps)%x)
3462	agents(i_ag)%path_y(path_ag) = path(steps)%y + rn_gate &
3463	* (path(steps)%y_s - path(steps)%y)
3464	steps = steps - 1
3465	path_ag = path_ag + 1
3466	ENDDO
3467	!
3468	!-- Set current intermittent target of this agent
3469	agents(i_ag)%path_counter = 1
3470	DEALLOCATE(tmp_mesh, path)
3471	CALL cpu_log( log_point_s(20), 'mas_nav_find_path', 'stop' )
3472
3473	END SUBROUTINE mas_nav_find_path
3474
3475	!------------------------------------------------------------------------------!
3476	! Description:
3477	! ------------
3478	!> Reduces the size of connection array to the amount of actual connections
3479	!> after all connetions were added to a mesh point
3480	!------------------------------------------------------------------------------!
3481	SUBROUTINE mas_nav_reduce_connections ( in_mp )
3482
3483	IMPLICIT NONE
3484
3485	INTEGER(iwp) :: noc !< number of connections
3486
3487	INTEGER, DIMENSION(:), ALLOCATABLE :: dum_cv !< dummy connected_vertices
3488
3489	REAL(wp), DIMENSION(:), ALLOCATABLE :: dum_dtv !< dummy distance_to_vertex
3490
3491	TYPE(mesh_point) :: in_mp
3492
3493	noc = in_mp%noc
3494	ALLOCATE( dum_cv(1:noc),dum_dtv(1:noc) )
3495	dum_cv = in_mp%connected_vertices(1:noc)
3496	dum_dtv = in_mp%distance_to_vertex(1:noc)
3497	DEALLOCATE( in_mp%connected_vertices, in_mp%distance_to_vertex )
3498	ALLOCATE( in_mp%connected_vertices(1:noc), &
3499	in_mp%distance_to_vertex(1:noc) )
3500	in_mp%connected_vertices(1:noc) = dum_cv(1:noc)
3501	in_mp%distance_to_vertex(1:noc) = dum_dtv(1:noc)
3502
3503	END SUBROUTINE mas_nav_reduce_connections
3504
3505	!------------------------------------------------------------------------------!
3506	! Description:
3507	! ------------
3508	!> Initializes a point of the navigation mesh
3509	!------------------------------------------------------------------------------!
3510	SUBROUTINE mas_nav_init_mesh_point ( in_mp, pid, vid, x, y )
3511
3512	IMPLICIT NONE
3513
3514	INTEGER(iwp) :: pid !< polygon ID
3515	INTEGER(iwp) :: vid !< vertex ID
3516
3517	REAL(wp) :: x !< x-coordinate
3518	REAL(wp) :: y !< y-coordinate
3519
3520	TYPE(mesh_point) :: in_mp !< mesh point to be initialized
3521
3522	in_mp%origin_id = -1
3523	in_mp%polygon_id = pid
3524	in_mp%vertex_id = vid
3525	in_mp%cost_so_far = 1.d12
3526	in_mp%x = x
3527	in_mp%y = y
3528	in_mp%x_s = x
3529	in_mp%y_s = y
3530	ALLOCATE(in_mp%connected_vertices(1:100), &
3531	in_mp%distance_to_vertex(1:100))
3532	in_mp%connected_vertices = -999
3533	in_mp%distance_to_vertex = -999.
3534	in_mp%noc = 0
3535
3536	END SUBROUTINE mas_nav_init_mesh_point
3537
3538	!------------------------------------------------------------------------------!
3539	! Description:
3540	! ------------
3541	!> Reading of namlist from parin file
3542	!------------------------------------------------------------------------------!
3543	SUBROUTINE mas_parin
3544
3545	USE control_parameters, &
3546	ONLY: agent_time_unlimited
3547
3548	IMPLICIT NONE
3549
3550	CHARACTER (LEN=80) :: line !<
3551
3552	NAMELIST /agents_par/ a_rand_target, adx, ady, agent_maximum_age, &
3553	agent_time_unlimited, alloc_factor_mas, asl, asn,&
3554	asr, ass, at_x, at_y, bc_mas_lr, bc_mas_ns, &
3555	coll_t_0, corner_gate_start, corner_gate_width, &
3556	deallocate_memory_mas, dist_to_int_target, &
3557	dt_agent, dt_arel, dt_write_agent_data,&
3558	end_time_arel, max_dist_from_path, min_nr_agent, &
3559	multi_agent_system_start, number_of_agent_groups,&
3560	radius_agent, random_start_position_agents, &
3561	read_agents_from_restartfile, repuls_agent, &
3562	repuls_wall, scan_radius_agent, sigma_rep_agent, &
3563	sigma_rep_wall, step_dealloc_mas, tau_accel_agent
3564
3565	!
3566	!-- Try to find agent package
3567	REWIND ( 11 )
3568	line = ' '
3569	DO WHILE ( INDEX( line, '&agents_par' ) == 0 )
3570	READ ( 11, '(A)', END=20 ) line
3571	ENDDO
3572	BACKSPACE ( 11 )
3573
3574	!
3575	!-- Read user-defined namelist
3576	READ ( 11, agents_par )
3577
3578	!
3579	!-- Set flag that indicates that agents are switched on
3580	agents_active = .TRUE.
3581
3582	20 CONTINUE
3583
3584	END SUBROUTINE mas_parin
3585
3586	!------------------------------------------------------------------------------!
3587	! Description:
3588	! ------------
3589	!> Routine for the whole processor
3590	!> Sort all agents into the 4 respective subgrid boxes
3591	!------------------------------------------------------------------------------!
3592	SUBROUTINE mas_ps_sort_in_subboxes
3593
3594	IMPLICIT NONE
3595
3596	INTEGER(iwp) :: i !< grid box (x)
3597	INTEGER(iwp) :: ip !< counter (x)
3598	INTEGER(iwp) :: is !< box counter
3599	INTEGER(iwp) :: j !< grid box (y)
3600	INTEGER(iwp) :: jp !< counter (y)
3601	INTEGER(iwp) :: m !< sorting index
3602	INTEGER(iwp) :: n !< agent index
3603	INTEGER(iwp) :: nn !< agent counter
3604	INTEGER(iwp) :: sort_index !< sorting index
3605
3606	INTEGER(iwp), DIMENSION(0:3) :: sort_count !< number of agents in one subbox
3607
3608	TYPE(agent_type), DIMENSION(:,:), ALLOCATABLE :: sort_agents !< sorted agent array
3609
3610	CALL cpu_log( log_point_s(21), 'mas_ps_sort_in_subboxes', 'start' )
3611	DO ip = nxl, nxr
3612	DO jp = nys, nyn
3613	number_of_agents = agt_count(jp,ip)
3614	IF ( number_of_agents <= 0 ) CYCLE
3615	agents => grid_agents(jp,ip)%agents(1:number_of_agents)
3616
3617	nn = 0
3618	sort_count = 0
3619	ALLOCATE( sort_agents(number_of_agents, 0:3) )
3620
3621	DO n = 1, number_of_agents
3622	sort_index = 0
3623
3624	IF ( agents(n)%agent_mask ) THEN
3625	nn = nn + 1
3626	!
3627	!-- Sorting agents with a binary scheme
3628	!-- sort_index=11_2=3_10 -> agent at the left,south subgridbox
3629	!-- sort_index=10_2=2_10 -> agent at the left,north subgridbox
3630	!-- sort_index=01_2=1_10 -> agent at the right,south subgridbox
3631	!-- sort_index=00_2=0_10 -> agent at the right,north subgridbox
3632	!-- For this the center of the gridbox is calculated
3633	i = (agents(n)%x + 0.5_wp * dx) * ddx
3634	j = (agents(n)%y + 0.5_wp * dy) * ddy
3635
3636	IF ( i == ip ) sort_index = sort_index + 2
3637	IF ( j == jp ) sort_index = sort_index + 1
3638
3639	sort_count(sort_index) = sort_count(sort_index) + 1
3640	m = sort_count(sort_index)
3641	sort_agents(m,sort_index) = agents(n)
3642	sort_agents(m,sort_index)%block_nr = sort_index
3643	ENDIF
3644	ENDDO
3645
3646	nn = 0
3647	DO is = 0,3
3648	grid_agents(jp,ip)%start_index(is) = nn + 1
3649	DO n = 1,sort_count(is)
3650	nn = nn + 1
3651	agents(nn) = sort_agents(n,is)
3652	ENDDO
3653	grid_agents(jp,ip)%end_index(is) = nn
3654	ENDDO
3655
3656	number_of_agents = nn
3657	agt_count(jp,ip) = number_of_agents
3658	DEALLOCATE(sort_agents)
3659	ENDDO
3660	ENDDO
3661	CALL cpu_log( log_point_s(21), 'mas_ps_sort_in_subboxes', 'stop' )
3662
3663	END SUBROUTINE mas_ps_sort_in_subboxes
3664
3665	!------------------------------------------------------------------------------!
3666	! Description:
3667	! ------------
3668	!> Move all agents not marked for deletion to lowest indices (packing)
3669	!------------------------------------------------------------------------------!
3670	SUBROUTINE mas_ps_pack
3671
3672	IMPLICIT NONE
3673
3674	INTEGER(iwp) :: n !< agent counter
3675	INTEGER(iwp) :: nn !< number of agents
3676	!
3677	!-- Find out elements marked for deletion and move data from highest index
3678	!-- values to these free indices
3679	nn = number_of_agents
3680
3681	DO WHILE ( .NOT. agents(nn)%agent_mask )
3682	nn = nn-1
3683	IF ( nn == 0 ) EXIT
3684	ENDDO
3685
3686	IF ( nn > 0 ) THEN
3687	DO n = 1, number_of_agents
3688	IF ( .NOT. agents(n)%agent_mask ) THEN
3689	agents(n) = agents(nn)
3690	nn = nn - 1
3691	DO WHILE ( .NOT. agents(nn)%agent_mask )
3692	nn = nn-1
3693	IF ( n == nn ) EXIT
3694	ENDDO
3695	ENDIF
3696	IF ( n == nn ) EXIT
3697	ENDDO
3698	ENDIF
3699
3700	!
3701	!-- The number of deleted agents has been determined in routines
3702	!-- mas_boundary_conds, mas_droplet_collision, and mas_eh_exchange_horiz
3703	number_of_agents = nn
3704
3705	END SUBROUTINE mas_ps_pack
3706
3707	!------------------------------------------------------------------------------!
3708	! Description:
3709	! ------------
3710	!> Sort agents in each sub-grid box into two groups: agents that already
3711	!> completed the LES timestep, and agents that need further timestepping to
3712	!> complete the LES timestep.
3713	!------------------------------------------------------------------------------!
3714	SUBROUTINE mas_ps_sort_timeloop_done
3715
3716	IMPLICIT NONE
3717
3718	INTEGER(iwp) :: end_index !< agent end index for each sub-box
3719	INTEGER(iwp) :: i !< index of agent grid box in x-direction
3720	INTEGER(iwp) :: j !< index of agent grid box in y-direction
3721	INTEGER(iwp) :: n !< running index for number of agents
3722	INTEGER(iwp) :: nb !< index of subgrid boux
3723	INTEGER(iwp) :: nf !< indices for agents in each sub-box that already finalized their substeps
3724	INTEGER(iwp) :: nnf !< indices for agents in each sub-box that need further treatment
3725	INTEGER(iwp) :: num_finalized !< number of agents in each sub-box that already finalized their substeps
3726	INTEGER(iwp) :: start_index !< agent start index for each sub-box
3727
3728	TYPE(agent_type), DIMENSION(:), ALLOCATABLE :: sort_agents !< temporary agent array
3729
3730	DO i = nxl, nxr
3731	DO j = nys, nyn
3732
3733	number_of_agents = agt_count(j,i)
3734	IF ( number_of_agents <= 0 ) CYCLE
3735
3736	agents => grid_agents(j,i)%agents(1:number_of_agents)
3737
3738	DO nb = 0, 3
3739	!
3740	!-- Obtain start and end index for each subgrid box
3741	start_index = grid_agents(j,i)%start_index(nb)
3742	end_index = grid_agents(j,i)%end_index(nb)
3743	!
3744	!-- Allocate temporary array used for sorting
3745	ALLOCATE( sort_agents(start_index:end_index) )
3746	!
3747	!-- Determine number of agents already completed the LES
3748	!-- timestep, and write them into a temporary array
3749	nf = start_index
3750	num_finalized = 0
3751	DO n = start_index, end_index
3752	IF ( dt_3d - agents(n)%dt_sum < 1E-8_wp ) THEN
3753	sort_agents(nf) = agents(n)
3754	nf = nf + 1
3755	num_finalized = num_finalized + 1
3756	ENDIF
3757	ENDDO
3758	!
3759	!-- Determine number of agents that not completed the LES
3760	!-- timestep, and write them into a temporary array
3761	nnf = nf
3762	DO n = start_index, end_index
3763	IF ( dt_3d - agents(n)%dt_sum > 1E-8_wp ) THEN
3764	sort_agents(nnf) = agents(n)
3765	nnf = nnf + 1
3766	ENDIF
3767	ENDDO
3768	!
3769	!-- Write back sorted agents
3770	agents(start_index:end_index) = &
3771	sort_agents(start_index:end_index)
3772	!
3773	!-- Determine updated start_index, used to masked already
3774	!-- completed agents.
3775	grid_agents(j,i)%start_index(nb) = &
3776	grid_agents(j,i)%start_index(nb) &
3777	+ num_finalized
3778	!
3779	!-- Deallocate dummy array
3780	DEALLOCATE ( sort_agents )
3781	!
3782	!-- Finally, if number of non-completed agents is non zero
3783	!-- in any of the sub-boxes, set control flag appropriately.
3784	IF ( nnf > nf ) &
3785	grid_agents(j,i)%time_loop_done = .FALSE.
3786
3787	ENDDO
3788	ENDDO
3789	ENDDO
3790
3791	END SUBROUTINE mas_ps_sort_timeloop_done
3792
3793	!------------------------------------------------------------------------------!
3794	! Description:
3795	! ------------
3796	!> Calls social forces calculations
3797	!------------------------------------------------------------------------------!
3798	SUBROUTINE mas_timestep_forces_call ( ip, jp )
3799
3800	IMPLICIT NONE
3801
3802	INTEGER(iwp) :: ip !< counter, x-direction
3803	INTEGER(iwp) :: jp !< counter, y-direction
3804	INTEGER(iwp) :: n !< loop variable over all agents in a grid box
3805
3806	!
3807	!-- Get direction for all agents in current grid cell
3808	CALL mas_agent_direction
3809
3810	CALL cpu_log( log_point_s(9), 'mas_transport', 'continue' )
3811	DO n = 1, number_of_agents
3812
3813	force_x = 0.0_wp
3814	force_y = 0.0_wp
3815
3816	CALL mas_timestep_social_forces ( 'acceleration', n, ip, jp )
3817
3818	CALL mas_timestep_social_forces ( 'other_agents', n, ip, jp )
3819
3820	CALL mas_timestep_social_forces ( 'walls', n, ip, jp )
3821	!
3822	!-- Update forces
3823	agents(n)%force_x = force_x
3824	agents(n)%force_y = force_y
3825	ENDDO
3826
3827	CALL cpu_log( log_point_s(9), 'mas_transport', 'pause' )
3828
3829
3830	END SUBROUTINE mas_timestep_forces_call
3831
3832	!------------------------------------------------------------------------------!
3833	! Description:
3834	! ------------
3835	!> Euler timestep of agent transport
3836	!------------------------------------------------------------------------------!
3837	SUBROUTINE mas_timestep
3838
3839	IMPLICIT NONE
3840
3841	INTEGER(iwp) :: n !< loop variable over all agents in a grid box
3842
3843	REAL(wp) :: abs_v !< absolute value of velocity
3844	REAL(wp) :: abs_f !< absolute value of force
3845
3846	CALL cpu_log( log_point_s(9), 'mas_transport', 'continue' )
3847
3848	DO n = 1, number_of_agents
3849	!
3850	!-- Limit absolute force to a maximum to prevent unrealistic acceleration
3851	abs_f = SQRT((agents(n)%force_x)2 + (agents(n)%force_y)2)
3852	IF ( abs_f > 20. ) THEN
3853	agents(n)%force_x = agents(n)%force_x * 20. / abs_f
3854	agents(n)%force_y = agents(n)%force_y * 20. / abs_f
3855	ENDIF
3856	!
3857	!-- Update agent speed
3858	agents(n)%speed_x = agents(n)%speed_x + agents(n)%force_x * dt_agent
3859	agents(n)%speed_y = agents(n)%speed_y + agents(n)%force_y * dt_agent
3860	!
3861	!-- Reduction of agent speed to maximum agent speed
3862	abs_v = SQRT((agents(n)%speed_x)2 + (agents(n)%speed_y)2)
3863	IF ( abs_v > v_max_agent ) THEN
3864	agents(n)%speed_x = agents(n)%speed_x * v_max_agent / abs_v
3865	agents(n)%speed_y = agents(n)%speed_y * v_max_agent / abs_v
3866	ENDIF
3867	!
3868	!-- Update agent position
3869	agents(n)%x = agents(n)%x + agents(n)%speed_x * dt_agent
3870	agents(n)%y = agents(n)%y + agents(n)%speed_y * dt_agent
3871	!
3872	!-- Update absolute value of agent speed
3873	agents(n)%speed_abs = abs_v
3874	!
3875	!-- Increment the agent age and the total time that the agent
3876	!-- has advanced within the agent timestep procedure
3877	agents(n)%age_m = agents(n)%age
3878	agents(n)%age = agents(n)%age + dt_agent
3879	agents(n)%dt_sum = agents(n)%dt_sum + dt_agent
3880	!
3881	!-- Check whether there is still an agent that has not yet completed
3882	!-- the total LES timestep
3883	IF ( ( dt_3d - agents(n)%dt_sum ) > 1E-8_wp ) THEN
3884	dt_3d_reached_l_mas = .FALSE.
3885	ENDIF
3886
3887	ENDDO
3888
3889	CALL cpu_log( log_point_s(9), 'mas_transport', 'pause' )
3890
3891
3892	END SUBROUTINE mas_timestep
3893
3894	!------------------------------------------------------------------------------!
3895	! Description:
3896	! ------------
3897	!> Calculates the Social Forces (Helbing and Molnar, 1995) that the agent
3898	!> experiences due to acceleration towards target and repulsion by obstacles
3899	!------------------------------------------------------------------------------!
3900	SUBROUTINE mas_timestep_social_forces ( mode, nl, ip, jp )
3901
3902	USE constants, &
3903	ONLY: pi
3904
3905	IMPLICIT NONE
3906
3907	CHARACTER (LEN=*) :: mode !< identifier for the mode of calculation
3908
3909	INTEGER(iwp) :: ij_dum !< index of nearest wall
3910	INTEGER(iwp) :: il !< index variable along x
3911	INTEGER(iwp) :: ip !< index variable along x
3912	INTEGER(iwp) :: jl !< index variable along y
3913	INTEGER(iwp) :: jp !< index variable along y
3914	INTEGER(iwp) :: nl !< loop variable over all agents in a grid box
3915	INTEGER(iwp) :: no !< loop variable over all agents in a grid box
3916	INTEGER(iwp) :: noa !< amount of agents in a grid box
3917	INTEGER(iwp) :: sc_x_end !< index for scan for topography/other agents
3918	INTEGER(iwp) :: sc_x_start !< index for scan for topography/other agents
3919	INTEGER(iwp) :: sc_y_end !< index for scan for topography/other agents
3920	INTEGER(iwp) :: sc_y_start !< index for scan for topography/other agents
3921
3922	LOGICAL :: corner_found !< flag that indicates a corner has been found near agent
3923
3924	REAL(wp) :: a_pl !< factor for collision avoidance
3925	REAL(wp) :: ax_semimaj !< semiminor axis of repulsive ellipse
3926	REAL(wp) :: b_pl !< factor for collision avoidance
3927	REAL(wp) :: c_pl !< factor for collision avoidance
3928	REAL(wp) :: coll_t !< time at which the next collision would happen
3929	REAL(wp) :: d_coll_t_0 !< inverse of collision cutoff time
3930	REAL(wp) :: d_pl !< factor for collision avoidance
3931	REAL(wp) :: ddum_f !< dummy devisor collision avoidance
3932	REAL(wp) :: dist !< distance to obstacle
3933	REAL(wp) :: dist_sq !< distance to obstacle squared
3934	REAL(wp) :: dummy_coll_time !< dummy for collision time
3935	REAL(wp) :: pos_rel_x !< relative position of two agents (x)
3936	REAL(wp) :: pos_rel_y !< relative position of two agents (y)
3937	REAL(wp) :: r_sq !< y-position
3938	REAL(wp) :: sra !< scan radius (agents)
3939	REAL(wp) :: srw !< local variable for scan radius (walls)
3940	REAL(wp) :: v_rel_x !< relative velocity (x); collision avoidance
3941	REAL(wp) :: v_rel_y !< relative velocity (y); collision avoidance
3942	REAL(wp) :: x_a !< x-position
3943	REAL(wp) :: x_wall !< x-position of wall
3944	REAL(wp) :: y_a !< y-position
3945	REAL(wp) :: y_wall !< y-position of wall
3946
3947	REAL(wp), PARAMETER :: k_pl = 1.5 !< factor for collision avoidance
3948
3949	TYPE(agent_type), DIMENSION(:), POINTER :: l_agts !< agents that repulse current agent
3950
3951	!
3952	!-- Initialization
3953	x_a = agents(nl)%x
3954	y_a = agents(nl)%y
3955
3956	SELECT CASE ( TRIM( mode ) )
3957	!
3958	!-- Calculation of force due to agent trying to approach desired velocity
3959	CASE ( 'acceleration' )
3960
3961	force_x = force_x + d_tau_accel_agent &
3962	* ( agents(nl)%speed_des*agents(nl)%speed_e_x &
3963	-agents(nl)%speed_x )
3964
3965	force_y = force_y + d_tau_accel_agent &
3966	* ( agents(nl)%speed_des*agents(nl)%speed_e_y &
3967	-agents(nl)%speed_y )
3968
3969	!
3970	!-- Calculation of repulsive forces by other agents in a radius around the
3971	!-- current one
3972	CASE ( 'other_agents' )
3973	CALL cpu_log( log_point_s(16), 'mas_other_agents', 'continue' )
3974
3975	sra = scan_radius_agent
3976	d_coll_t_0 = 1./coll_t_0
3977	!
3978	!-- Find relevant gridboxes (those that could contain agents within
3979	!-- scan radius)
3980	sc_x_start = FLOOR( (x_a - sra) * ddx )
3981	sc_x_end = FLOOR( (x_a + sra) * ddx )
3982	sc_y_start = FLOOR( (y_a - sra) * ddx )
3983	sc_y_end = FLOOR( (y_a + sra) * ddx )
3984	IF ( sc_x_start < nxlg ) sc_x_start = nxlg
3985	IF ( sc_x_end > nxrg ) sc_x_end = nxrg
3986	IF ( sc_y_start < nysg ) sc_y_start = nysg
3987	IF ( sc_y_end > nyng ) sc_y_end = nyng
3988
3989	sra = sra**2
3990	!
3991	!-- Loop over all previously found relevant gridboxes
3992	DO il = sc_x_start, sc_x_end
3993	DO jl = sc_y_start, sc_y_end
3994	noa = agt_count(jl,il)
3995	IF ( noa <= 0 ) CYCLE
3996	l_agts => grid_agents(jl,il)%agents(1:noa)
3997	DO no = 1, noa
3998	!
3999	!-- Skip self
4000	IF ( jl == jp .AND. il == ip .AND. no == nl ) CYCLE
4001	pos_rel_x = l_agts(no)%x - x_a
4002	pos_rel_y = l_agts(no)%y - y_a
4003	dist_sq = pos_rel_x2 + pos_rel_y2
4004	IF ( dist_sq > sra ) CYCLE
4005	r_sq = (2radius_agent)*2
4006	v_rel_x = agents(nl)%speed_x - l_agts(no)%speed_x
4007	v_rel_y = agents(nl)%speed_y - l_agts(no)%speed_y
4008	!
4009	!-- Collision is already occuring, default to standard
4010	!-- social forces
4011	IF ( dist_sq <= r_sq ) THEN
4012	dist = SQRT(dist_sq) + 1.0d-12
4013	ax_semimaj = .5_wp*SQRT( dist )
4014
4015	force_x = force_x - 0.125_wp * repuls_agent &
4016	* d_sigma_rep_agent / ax_semimaj &
4017	* EXP( -ax_semimaj*d_sigma_rep_agent ) &
4018	* (pos_rel_x/dist)
4019
4020	force_y = force_y - 0.125_wp * repuls_agent &
4021	* d_sigma_rep_agent / ax_semimaj &
4022	* EXP( -ax_semimaj*d_sigma_rep_agent ) &
4023	* (pos_rel_y/dist)
4024	!
4025	!-- Currently no collision, calculate collision avoidance
4026	!-- force according to Karamouzas et al (2014, PRL 113,238701)
4027	ELSE
4028	!
4029	!-- factors
4030	a_pl = v_rel_x2 + v_rel_y2
4031	b_pl = pos_rel_xv_rel_x + pos_rel_yv_rel_y
4032	c_pl = dist_sq - r_sq
4033	d_pl = b_pl*2 - a_plc_pl
4034	!
4035	!-- If the two agents are moving non-parallel, calculate
4036	!-- collision avoidance social force
4037	IF ( d_pl > 0.0_wp .AND. &
4038	( a_pl < -0.00001 .OR. a_pl > 0.00001 ) ) &
4039	THEN
4040
4041	d_pl = SQRT(d_pl)
4042	coll_t = (b_pl - d_pl)/a_pl
4043	IF ( coll_t > 0.0_wp ) THEN
4044	!
4045	!-- Dummy factor
4046	ddum_f = 1. / ( a_pl * coll_t**2 ) &
4047	* ( 2. / coll_t + 1.0 * d_coll_t_0 )
4048	!
4049	!-- x-component of social force
4050	force_x = force_x - k_pl * &
4051	EXP( -coll_t * d_coll_t_0 ) * &
4052	( v_rel_x - &
4053	( b_pl * v_rel_x - &
4054	a_pl * pos_rel_x ) / d_pl ) * &
4055	ddum_f
4056	!
4057	!-- y-component of social force
4058	force_y = force_y - k_pl * &
4059	EXP( -coll_t * d_coll_t_0 ) * &
4060	( v_rel_y - &
4061	( b_pl * v_rel_y - &
4062	a_pl * pos_rel_y ) / d_pl ) * &
4063	ddum_f
4064
4065	ENDIF
4066	ENDIF
4067	ENDIF
4068	ENDDO
4069	ENDDO
4070	ENDDO
4071	CALL cpu_log( log_point_s(16), 'mas_other_agents', 'pause' )
4072
4073	CASE ( 'walls' )
4074
4075	srw = scan_radius_wall
4076	corner_found = .FALSE.
4077	!
4078	!-- find relevant grid boxes (those that could contain topography
4079	!-- within radius)
4080	sc_x_start = (x_a - srw) * ddx
4081	sc_x_end = (x_a + srw) * ddx
4082	sc_y_start = (y_a - srw) * ddx
4083	sc_y_end = (y_a + srw) * ddx
4084	IF ( sc_x_start < nxlg ) sc_x_start = nxlg
4085	IF ( sc_x_end > nxrg ) sc_x_end = nxrg
4086	IF ( sc_y_start < nysg ) sc_y_start = nysg
4087	IF ( sc_y_end > nyng ) sc_y_end = nyng
4088	!
4089	!-- Find "walls" ( i.e. topography steps (up or down) higher than one
4090	!-- grid box ) that are perpendicular to the agent within the defined
4091	!-- search radius. Such obstacles cannot be passed and a social force
4092	!-- to that effect is applied.
4093	!-- Walls only apply a force perpendicular to the wall to the agent.
4094	!-- There is therefore a search for walls directly right, left, south
4095	!-- and north of the agent. All other walls are ignored.
4096	!--
4097	!-- Check for wall left of current agent
4098	ij_dum = 0
4099	IF ( sc_x_start < ip ) THEN
4100	DO il = ip - 1, sc_x_start, -1
4101	!
4102	!-- Going left from the agent, check for a right wall
4103	IF ( BTEST( obstacle_flags(jp,il), 2 ) ) THEN
4104	!
4105	!-- obstacle found in grid box il, wall at right side
4106	x_wall = (il+1)*dx
4107	!
4108	!-- Calculate force of found wall on agent
4109	CALL mas_timestep_wall_corner_force ( nl, x_a, x_wall, &
4110	y_a, y_a )
4111	!
4112	!-- calculate new x starting index for later scan for corners
4113	ij_dum = il + 1
4114	EXIT
4115	ENDIF
4116	ENDDO
4117	ENDIF
4118	IF ( ij_dum /= 0 ) sc_x_start = ij_dum
4119
4120	!
4121	!-- Check for wall right of current agent
4122	ij_dum = 0
4123	IF ( sc_x_end > ip ) THEN
4124	DO il = ip + 1, sc_x_end
4125	!
4126	!-- Going right from the agent, check for a left wall
4127	IF ( BTEST( obstacle_flags(jp,il), 6 ) ) THEN
4128	!
4129	!-- obstacle found in grid box il, wall at left side
4130	x_wall = il*dx
4131	!
4132	!-- Calculate force of found wall on agent
4133	CALL mas_timestep_wall_corner_force ( nl, x_a, x_wall, &
4134	y_a, y_a )
4135	!
4136	!-- calculate new x end index for later scan for corners
4137	ij_dum = il - 1
4138	EXIT
4139	ENDIF
4140	ENDDO
4141	ENDIF
4142	IF ( ij_dum /= 0 ) sc_x_end = ij_dum
4143
4144	!
4145	!-- Check for wall south of current agent
4146	ij_dum = 0
4147	IF ( sc_y_start < jp ) THEN
4148	DO jl = jp - 1, sc_y_start, -1
4149	!
4150	!-- Going south from the agent, check for a north wall
4151	IF ( BTEST( obstacle_flags(jl,ip), 0 ) ) THEN
4152	!
4153	!-- obstacle found in grid box jl, wall at left side
4154	y_wall = (jl+1)*dy
4155
4156	CALL mas_timestep_wall_corner_force ( nl, x_a, x_a, y_a, &
4157	y_wall )
4158	!
4159	!-- calculate new y starting index for later scan for corners
4160	ij_dum = jl + 1
4161	EXIT
4162	ENDIF
4163	ENDDO
4164	ENDIF
4165	IF ( ij_dum /= 0 ) sc_y_start = ij_dum
4166
4167	!
4168	!-- Check for wall north of current agent
4169	ij_dum = 0
4170	IF ( sc_y_end > jp ) THEN
4171	DO jl = jp + 1, sc_y_end
4172	!
4173	!-- Going north from the agent, check for a south wall
4174	IF ( BTEST( obstacle_flags(jl,ip), 4 ) ) THEN
4175	!
4176	!-- obstacle found in grid box jl, wall at left side
4177	y_wall = jl*dy
4178
4179	CALL mas_timestep_wall_corner_force ( nl, x_a, x_a, y_a, &
4180	y_wall )
4181	!
4182	!-- calculate new y end index for later scan for corners
4183	ij_dum = jl - 1
4184	ENDIF
4185	ENDDO
4186	ENDIF
4187	IF ( ij_dum /= 0 ) sc_y_end = ij_dum
4188
4189	!
4190	!-- Scan for corners surrounding current agent.
4191	!-- Only gridcells that are closer than the closest wall in each
4192	!-- direction (n,s,r,l) are considered in the search since those
4193	!-- further away would have a significantly smaller resulting force
4194	!-- than the closer wall.
4195	DO il = sc_x_start, sc_x_end
4196	DO jl = sc_y_start, sc_y_end
4197	IF ( il == ip .OR. jl == jp ) CYCLE
4198	!
4199	!-- corners left of agent
4200	IF ( il < ip ) THEN
4201	!
4202	!-- south left quadrant: look for north right corner
4203	IF ( jl < jp ) THEN
4204	IF ( BTEST( obstacle_flags(jl,il), 1 ) ) THEN
4205	!
4206	!-- calculate coordinates of the found corner
4207	x_wall = (il+1)*dx
4208	y_wall = (jl+1)*dy
4209
4210	CALL mas_timestep_wall_corner_force ( nl, x_a, &
4211	x_wall, y_a, y_wall )
4212
4213	ENDIF
4214	!
4215	!-- north left quadrant: look for south right corner
4216	ELSEIF ( jl > jp ) THEN
4217	IF ( BTEST( obstacle_flags(jl,il), 3 ) ) THEN
4218	!
4219	!-- calculate coordinates of the corner of said gridcell
4220	!-- that is closest to the current agent
4221	x_wall = (il+1)*dx
4222	y_wall = jl*dy
4223
4224	CALL mas_timestep_wall_corner_force ( nl, x_a, &
4225	x_wall, y_a, y_wall )
4226
4227	ENDIF
4228	ENDIF
4229	ELSEIF ( il > ip ) THEN
4230	!
4231	!-- south right quadrant: look for north left corner
4232	IF ( jl < jp ) THEN
4233	IF ( BTEST( obstacle_flags(jl,il), 7 ) ) THEN
4234	!
4235	!-- calculate coordinates of the corner of said gridcell
4236	!-- that is closest to the current agent
4237	x_wall = il*dx
4238	y_wall = (jl+1)*dy
4239
4240	CALL mas_timestep_wall_corner_force ( nl, x_a, &
4241	x_wall, y_a, y_wall )
4242
4243	ENDIF
4244	!
4245	!-- north right quadrant: look for south left corner
4246	ELSEIF ( jl > jp ) THEN
4247	IF ( BTEST( obstacle_flags(jl,il), 5 ) ) THEN
4248	!
4249	!-- calculate coordinates of the corner of said gridcell
4250	!-- that is closest to the current agent
4251	x_wall = il*dx
4252	y_wall = jl*dy
4253
4254	CALL mas_timestep_wall_corner_force ( nl, x_a, &
4255	x_wall, y_a, y_wall )
4256
4257	ENDIF
4258	ENDIF
4259	ENDIF
4260	ENDDO
4261	ENDDO
4262
4263	CASE DEFAULT
4264
4265	END SELECT
4266
4267	END SUBROUTINE mas_timestep_social_forces
4268
4269	!------------------------------------------------------------------------------!
4270	! Description:
4271	! ------------
4272	!> Given a distance to the current agent, calculates the force a found corner
4273	!> or wall exerts on that agent
4274	!------------------------------------------------------------------------------!
4275	SUBROUTINE mas_timestep_wall_corner_force ( nl, xa, xw, ya, yw )
4276
4277	IMPLICIT NONE
4278
4279	INTEGER(iwp) :: nl !< loop variable over all agents in a grid box
4280
4281	REAL(wp) :: dist_l !< distance to obstacle
4282	REAL(wp) :: force_d_x !< increment of social force, x-direction
4283	REAL(wp) :: force_d_y !< increment of social force, x-direction
4284	REAL(wp) :: xa !< x-position of agent
4285	REAL(wp) :: xw !< x-position of wall
4286	REAL(wp) :: ya !< x-position of agent
4287	REAL(wp) :: yw !< y-position of wall
4288
4289	force_d_x = 0.0_wp
4290	force_d_y = 0.0_wp
4291	!
4292	!-- calculate coordinates of corner relative to agent
4293	!-- postion and distance between corner and agent
4294	xw = xa - xw
4295	yw = ya - yw
4296	dist_l = SQRT( (xw)2 + (yw)2 )
4297	!
4298	!-- calculate x and y component of repulsive force
4299	!-- induced by previously found corner
4300	IF ( dist_l > 0 ) THEN
4301	force_d_x = repuls_wall * d_sigma_rep_wall &
4302	* EXP( -dist_l * d_sigma_rep_wall ) &
4303	* xw / (dist_l)
4304	force_d_y = repuls_wall * d_sigma_rep_wall &
4305	* EXP( -dist_l * d_sigma_rep_wall ) &
4306	* yw / (dist_l)
4307	ENDIF
4308
4309	! !-- forces that are located outside of a sight radius of
4310	! !-- 200Â° (-> COS(100./180.pi) = COS(.555pi)) of
4311	! !-- current agent are considered to have an effect of 50%
4312	! IF ( force_d_x * agents(nl)%speed_e_x + &
4313	! force_d_y * agents(nl)%speed_e_y < &
4314	! SQRT(force_d_x2 + force_d_y2) * &
4315	! COS( .55555555 * 3.1415 ) ) &
4316	! THEN
4317	! force_d_x = force_d_x * .5_wp
4318	! force_d_y = force_d_y * .5_wp
4319	! ENDIF
4320
4321	!
4322	!-- add force increment to total force of current agent
4323	force_x = force_x + force_d_x
4324	force_y = force_y + force_d_y
4325
4326	END SUBROUTINE mas_timestep_wall_corner_force
4327
4328	!
4329	!-- Calculates distance of point P to edge (A,B). If A = B, calculates
4330	!-- point-to-point distance from A/B to P
4331	FUNCTION dist_point_to_edge ( a_x, a_y, b_x, b_y, p_x, p_y )
4332
4333	IMPLICIT NONE
4334
4335	REAL(wp) :: ab_x !< x-coordinate of vector from A to B
4336	REAL(wp) :: ab_y !< y-coordinate of vector from A to B
4337	REAL(wp) :: ab_d !< inverse length of vector from A to B
4338	REAL(wp) :: ab_u_x !< x-coordinate of vector with direction of ab and length 1
4339	REAL(wp) :: ab_u_y !< y-coordinate of vector with direction of ab and length 1
4340	REAL(wp) :: ba_x !< x-coordinate of vector from B to A
4341	REAL(wp) :: ba_y !< y-coordinate of vector from B to A
4342	REAL(wp) :: ap_x !< x-coordinate of vector from A to P
4343	REAL(wp) :: ap_y !< y-coordinate of vector from A to P
4344	REAL(wp) :: bp_x !< x-coordinate of vector from B to P
4345	REAL(wp) :: bp_y !< y-coordinate of vector from B to P
4346	REAL(wp) :: a_x !< x-coordinate of point A of edge
4347	REAL(wp) :: a_y !< y-coordinate of point A of edge
4348	REAL(wp) :: b_x !< x-coordinate of point B of edge
4349	REAL(wp) :: b_y !< y-coordinate of point B of edge
4350	REAL(wp) :: p_x !< x-coordinate of point P
4351	REAL(wp) :: p_y !< y-coordinate of point P
4352	REAL(wp) :: dist_x !< x-coordinate of point P
4353	REAL(wp) :: dist_y !< y-coordinate of point P
4354	REAL(wp) :: dist_point_to_edge !< y-coordinate of point P
4355
4356	ab_x = - a_x + b_x
4357	ab_y = - a_y + b_y
4358	ba_x = - b_x + a_x
4359	ba_y = - b_y + a_y
4360	ap_x = - a_x + p_x
4361	ap_y = - a_y + p_y
4362	bp_x = - b_x + p_x
4363	bp_y = - b_y + p_y
4364
4365	IF ( ab_x * ap_x + ab_y * ap_y <= 0. ) THEN
4366	dist_point_to_edge = SQRT((a_x - p_x)2 + (a_y - p_y)2)
4367	ELSEIF ( ba_x * bp_x + ba_y * bp_y <= 0. ) THEN
4368	dist_point_to_edge = SQRT((b_x - p_x)2 + (b_y - p_y)2)
4369	ELSE
4370	ab_d = 1./SQRT((ab_x)2+(ab_y)2)
4371	ab_u_x = ab_x*ab_d
4372	ab_u_y = ab_y*ab_d
4373	dist_x = ap_x - (ap_xab_u_x+ap_yab_u_y)*ab_u_x
4374	dist_y = ap_y - (ap_xab_u_x+ap_yab_u_y)*ab_u_y
4375	dist_point_to_edge = SQRT( dist_x2 + dist_y2 )
4376	ENDIF
4377
4378	END FUNCTION dist_point_to_edge
4379
4380	!
4381	!-- Returns the heuristic between points A and B (currently the straight
4382	!-- distance)
4383	FUNCTION heuristic ( ax, ay, bx, by )
4384
4385	IMPLICIT NONE
4386
4387	REAL(wp) :: ax !< x-coordinate of point A
4388	REAL(wp) :: ay !< y-coordinate of point A
4389	REAL(wp) :: bx !< x-coordinate of point B
4390	REAL(wp) :: by !< y-coordinate of point B
4391	REAL(wp) :: heuristic !< return value
4392
4393	heuristic = SQRT(( ax - bx )2 + ( ay - by )2)
4394
4395	END FUNCTION heuristic
4396
4397	!
4398	!-- Calculates if point P is left of the infinite
4399	!-- line that contains A and B (direction: A to B)
4400	!-- Concept: 2D rotation of two vectors
4401	FUNCTION is_left ( ax, ay, bx, by, px, py )
4402
4403	IMPLICIT NONE
4404
4405	LOGICAL :: is_left !< return value; TRUE if P is left of AB
4406
4407	REAL(wp) :: ax !< x-coordinate of point A
4408	REAL(wp) :: ay !< y-coordinate of point A
4409	REAL(wp) :: bx !< x-coordinate of point B
4410	REAL(wp) :: by !< y-coordinate of point B
4411	REAL(wp) :: px !< x-coordinate of point P
4412	REAL(wp) :: py !< y-coordinate of point P
4413
4414	is_left = (bx-ax)(py-ay)-(px-ax)(by-ay) > 0
4415	IF ( (ABS(ax-px) < .001 .AND. ABS(ay-py) < .001) .OR. &
4416	(ABS(bx-px) < .001 .AND. ABS(by-py) < .001) ) &
4417	THEN
4418	is_left = .FALSE.
4419	ENDIF
4420
4421	RETURN
4422
4423	END FUNCTION is_left
4424
4425	!
4426	!-- Calculates if point P is right of the infinite
4427	!-- line that contains A and B (direction: A to B)
4428	!-- Concept: 2D rotation of two vectors
4429	FUNCTION is_right ( ax, ay, bx, by, px, py )
4430
4431	IMPLICIT NONE
4432
4433	LOGICAL :: is_right !< return value; TRUE if P is right of AB
4434
4435	REAL(wp), INTENT(IN) :: ax !< x-coordinate of point A
4436	REAL(wp), INTENT(IN) :: ay !< y-coordinate of point A
4437	REAL(wp), INTENT(IN) :: bx !< x-coordinate of point B
4438	REAL(wp), INTENT(IN) :: by !< y-coordinate of point B
4439	REAL(wp), INTENT(IN) :: px !< x-coordinate of point P
4440	REAL(wp), INTENT(IN) :: py !< y-coordinate of point P
4441
4442	is_right = (bx-ax)(py-ay)-(px-ax)(by-ay) < 0
4443	IF ( (ABS(ax-px) < .001 .AND. ABS(ay-py) < .001) .OR. &
4444	(ABS(bx-px) < .001 .AND. ABS(by-py) < .001) ) &
4445	THEN
4446	is_right = .FALSE.
4447	ENDIF
4448
4449	RETURN
4450
4451	END FUNCTION is_right
4452
4453	!
4454	!-- Returns true if the line segments AB and PQ share an intersection
4455	FUNCTION intersect ( ax, ay, bx, by, px, py, qx, qy )
4456
4457	IMPLICIT NONE
4458
4459	LOGICAL :: intersect !< return value; TRUE if intersection was found
4460	LOGICAL :: la !< T if a is left of PQ
4461	LOGICAL :: lb !< T if b is left of PQ
4462	LOGICAL :: lp !< T if p is left of AB
4463	LOGICAL :: lq !< T if q is left of AB
4464	LOGICAL :: poss !< flag that indicates if an intersection is still possible
4465	LOGICAL :: ra !< T if a is right of PQ
4466	LOGICAL :: rb !< T if b is right of PQ
4467	LOGICAL :: rp !< T if p is right of AB
4468	LOGICAL :: rq !< T if q is right of AB
4469
4470	REAL(wp) :: ax !< x-coordinate of point A
4471	REAL(wp) :: ay !< y-coordinate of point A
4472	REAL(wp) :: bx !< x-coordinate of point B
4473	REAL(wp) :: by !< y-coordinate of point B
4474	REAL(wp) :: px !< x-coordinate of point P
4475	REAL(wp) :: py !< y-coordinate of point P
4476	REAL(wp) :: qx !< x-coordinate of point Q
4477	REAL(wp) :: qy !< y-coordinate of point Q
4478
4479	intersect = .FALSE.
4480	poss = .FALSE.
4481	!
4482	!-- Intersection is possible only if P and Q are on opposing sides of AB
4483	lp = is_left(ax,ay,bx,by,px,py)
4484	rq = is_right(ax,ay,bx,by,qx,qy)
4485	IF ( lp .AND. rq ) poss = .TRUE.
4486	IF ( .NOT. poss ) THEN
4487	lq = is_left(ax,ay,bx,by,qx,qy)
4488	rp = is_right(ax,ay,bx,by,px,py)
4489	IF ( lq .AND. rp ) poss = .TRUE.
4490	ENDIF
4491	!
4492	!-- Intersection occurs only if above test (poss) was true AND
4493	!-- A and B are on opposing sides of PQ
4494	IF ( poss ) THEN
4495	la = is_left(px,py,qx,qy,ax,ay)
4496	rb = is_right(px,py,qx,qy,bx,by)
4497	IF ( la .AND. rb ) intersect = .TRUE.
4498	IF ( .NOT. intersect ) THEN
4499	lb = is_left(px,py,qx,qy,bx,by)
4500	ra = is_right(px,py,qx,qy,ax,ay)
4501	IF ( lb .AND. ra ) intersect = .TRUE.
4502	ENDIF
4503	ENDIF
4504
4505	RETURN
4506
4507	END FUNCTION intersect
4508
4509	!
4510	!-- Gives a nuber randomly distributed around an average
4511	FUNCTION random_normal ( avg, variation )
4512
4513	IMPLICIT NONE
4514
4515	REAL(wp) :: avg !< x-coordinate of vector from A to B
4516	REAL(wp) :: variation !< y-coordinate of vector from A to B
4517	REAL(wp) :: random_normal !< y-coordinate of vector from A to B
4518
4519	REAL(wp), DIMENSION(12) :: random_arr !< inverse length of vector from A to B
4520
4521	CALL RANDOM_NUMBER(random_arr)
4522	random_normal = avg + variation*(SUM(random_arr)-6.)
4523
4524	END FUNCTION random_normal
4525
4526
4527	END MODULE multi_agent_system_mod

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