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source: palm/trunk/SOURCE/random_generator_parallel_mod.f90 @ 1850

Last change on this file since 1850 was 1850, checked in by maronga, 9 years ago
added _mod string to several filenames to meet the naming convection for modules
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1	!> @file random_generator_parallel_mod.f90
2	!------------------------------------------------------------------------------!
3	! This file is part of PALM.
4	!
5	! PALM is free software: you can redistribute it and/or modify it under the terms
6	! of the GNU General Public License as published by the Free Software Foundation,
7	! either version 3 of the License, or (at your option) any later version.
8	!
9	! PALM is distributed in the hope that it will be useful, but WITHOUT ANY
10	! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
11	! A PARTICULAR PURPOSE. See the GNU General Public License for more details.
12	!
13	! You should have received a copy of the GNU General Public License along with
14	! PALM. If not, see <http://www.gnu.org/licenses/>.
15	!
16	! Copyright 1997-2016 Leibniz Universitaet Hannover
17	!------------------------------------------------------------------------------!
18	!
19	! Current revisions:
20	! -----------------
21	! Module renamed
22	!
23	!
24	! Former revisions:
25	! -----------------
26	! $Id: random_generator_parallel_mod.f90 1850 2016-04-08 13:29:27Z maronga $
27	!
28	! 1682 2015-10-07 23:56:08Z knoop
29	! Code annotations made doxygen readable
30	!
31	! 1400 2014-05-09 14:03:54Z knoop
32	! Initial revision
33	!
34	!
35	! Description:
36	! ------------
37	!> This module contains and supports the random number generating routine ran_parallel.
38	!> ran_parallel returns a uniform random deviate between 0.0 and 1.0
39	!> (exclusive of the end point values).
40	!> Additionally it provides the generator with five integer for use as initial state space.
41	!> The first tree integers (iran, jran, kran) are maintained as non negative values,
42	!> while the last two (mran, nran) have 32-bit nonzero values.
43	!> Also provided by this module is support for initializing or reinitializing
44	!> the state space to a desired standard sequence number, hashing the initial
45	!> values to random values, and allocating and deallocating the internal workspace
46	!> Random number generator, produces numbers equally distributed in interval
47	!>
48	!> This routine is taken from the "numerical recipies vol. 2"
49	!------------------------------------------------------------------------------!
50	MODULE random_generator_parallel
51
52
53	USE kinds
54
55	IMPLICIT NONE
56
57	PRIVATE
58	PUBLIC random_number_parallel, random_seed_parallel, random_dummy, &
59	id_random_array, seq_random_array
60
61	INTEGER(isp), SAVE :: lenran=0 !<
62	INTEGER(isp), SAVE :: seq=0 !<
63	INTEGER(isp), SAVE :: iran0 !<
64	INTEGER(isp), SAVE :: jran0 !<
65	INTEGER(isp), SAVE :: kran0 !<
66	INTEGER(isp), SAVE :: mran0 !<
67	INTEGER(isp), SAVE :: nran0 !<
68	INTEGER(isp), SAVE :: rans !<
69
70	INTEGER(isp), DIMENSION(:, :), POINTER, SAVE :: ranseeds !<
71
72	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: iran !<
73	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: jran !<
74	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: kran !<
75	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: mran !<
76	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: nran !<
77	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: ranv !<
78
79
80
81	INTEGER(isp), DIMENSION(:,:), ALLOCATABLE :: id_random_array !<
82	INTEGER(isp), DIMENSION(:,:,:), ALLOCATABLE :: seq_random_array !<
83
84	REAL(wp), SAVE :: amm !<
85
86	REAL(wp) :: random_dummy=0.0 !<
87
88	INTERFACE random_number_parallel
89	MODULE PROCEDURE ran0_s
90	END INTERFACE
91
92	INTERFACE random_seed_parallel
93	MODULE PROCEDURE random_seed_parallel
94	END INTERFACE
95
96	INTERFACE ran_hash
97	MODULE PROCEDURE ran_hash_v
98	END INTERFACE
99
100	INTERFACE reallocate
101	MODULE PROCEDURE reallocate_iv,reallocate_im
102	END INTERFACE
103
104	INTERFACE arth
105	MODULE PROCEDURE arth_i
106	END INTERFACE
107
108	CONTAINS
109
110	!------------------------------------------------------------------------------!
111	! Description:
112	! ------------
113	!> Lagged Fibonacci generator combined with a Marsaglia shiftsequence.
114	!> Returns as harvest a uniform random deviate between 0.0 and 1.0 (exclusive of the end point values).
115	!> This generator has the same calling and initialization conventions as Fortran 90's random_number routine.
116	!> Use random_seed_parallel to initialize or reinitialize to a particular sequence.
117	!> The period of this generator is about 2.0 x 10^28, and it fully vectorizes.
118	!> Validity of the integer model assumed by this generator is tested at initialization.
119	!------------------------------------------------------------------------------!
120	SUBROUTINE ran0_s(harvest)
121
122	USE kinds
123
124	IMPLICIT NONE
125
126	REAL(wp), INTENT(OUT) :: harvest !<
127
128	IF (lenran < 1) CALL ran_init(1) !- Initialization routine in ran_state.
129
130	!- Update Fibonacci generator, which has period p^2 + p + 1, p = 2^31 - 69.
131	rans = iran0 - kran0
132
133	IF (rans < 0) rans = rans + 2147483579_isp
134
135	iran0 = jran0
136	jran0 = kran0
137	kran0 = rans
138
139	nran0 = ieor( nran0, ishft (nran0, 13) ) !- Update Marsaglia shift sequence with period 2^32 - 1.
140	nran0 = ieor( nran0, ishft (nran0, -17) )
141	nran0 = ieor( nran0, ishft (nran0, 5) )
142
143	rans = ieor( nran0, rans ) !- Combine the generators.
144
145	harvest = amm * merge( rans, not(rans), rans < 0 ) !- Make the result positive definite (note that amm is negative).
146
147	END SUBROUTINE ran0_s
148
149	!------------------------------------------------------------------------------!
150	! Description:
151	! ------------
152	!> Initialize or reinitialize the random generator state space to vectors of size length.
153	!> The saved variable seq is hashed (via calls to the module routine ran_hash)
154	!> to create unique starting seeds, different for each vector component.
155	!------------------------------------------------------------------------------!
156	SUBROUTINE ran_init( length )
157
158	USE kinds
159
160	IMPLICIT NONE
161
162	INTEGER(isp), INTENT(IN) :: length !<
163
164	INTEGER(isp), PARAMETER:: hg=huge(1_isp) !<
165	INTEGER(isp), PARAMETER:: hgm=-hg !<
166	INTEGER(isp), PARAMETER:: hgng=hgm-1 !<
167
168	INTEGER(isp) :: new !<
169	INTEGER(isp) :: j !<
170	INTEGER(isp) :: hgt !<
171
172	IF ( length < lenran ) RETURN !- Simply return if enough space is already allocated.
173
174	hgt = hg
175
176	!- The following lines check that kind value isp is in fact a 32-bit integer
177	!- with the usual properties that we expect it to have (under negation and wrap-around addition).
178	!- If all of these tests are satisfied, then the routines that use this module are portable,
179	!- even though they go beyond Fortran 90's integer model.
180
181	IF ( hg /= 2147483647 ) CALL ran_error('ran_init: arith assump 1 fails')
182	IF ( hgng >= 0 ) CALL ran_error('ran_init: arith assump 2 fails')
183	IF ( hgt+1 /= hgng ) CALL ran_error('ran_init: arith assump 3 fails')
184	IF ( not(hg) >= 0 ) CALL ran_error('ran_init: arith assump 4 fails')
185	IF ( not(hgng) < 0 ) CALL ran_error('ran_init: arith assump 5 fails')
186	IF ( hg+hgng >= 0 ) CALL ran_error('ran_init: arith assump 6 fails')
187	IF ( not(-1_isp) < 0 ) CALL ran_error('ran_init: arith assump 7 fails')
188	IF ( not(0_isp) >= 0 ) CALL ran_error('ran_init: arith assump 8 fails')
189	IF ( not(1_isp) >= 0 ) CALL ran_error('ran_init: arith assump 9 fails')
190
191	IF ( lenran > 0) THEN !- Reallocate space, or ...
192
193	ranseeds => reallocate( ranseeds, length, 5)
194	ranv => reallocate( ranv, length-1)
195	new = lenran+1
196
197	ELSE !- allocate space.
198
199	ALLOCATE(ranseeds(length,5))
200	ALLOCATE(ranv(length-1))
201	new = 1 !- Index of first location not yet initialized.
202	amm = nearest(1.0_wp,-1.0_wp)/hgng
203	!- Use of nearest is to ensure that returned random deviates are strictly lessthan 1.0.
204	IF (ammhgng >= 1.0 .or. ammhgng <= 0.0) &
205	CALL ran_error('ran_init: arith assump 10 fails')
206
207	END IF
208
209	!- Set starting values, unique by seq and vector component.
210	ranseeds(new:,1) = seq
211	ranseeds(new:,2:5)=spread(arth(new,1,size(ranseeds(new:,1))),2,4)
212
213	DO j=1,4 !- Hash them.
214	CALL ran_hash(ranseeds(new:,j), ranseeds(new:,j+1))
215	END DO
216
217	WHERE (ranseeds (new: ,1:3) < 0) &
218	ranseeds(new: ,1:3)=not(ranseeds(new: ,1:3)) !- Enforce nonnegativity.
219
220	WHERE (ranseeds(new: ,4:5) == 0) ranseeds(new: ,4:5)=1 !- Enforce nonzero.
221
222	IF (new == 1) THEN !- Set scalar seeds.
223
224	iran0 = ranseeds(1,1)
225	jran0 = ranseeds(1,2)
226	kran0 = ranseeds(1,3)
227	mran0 = ranseeds(1,4)
228	nran0 = ranseeds(1,5)
229	rans = nran0
230
231	END IF
232
233	IF (length > 1) THEN !- Point to vector seeds.
234
235	iran => ranseeds(2:,1)
236	jran => ranseeds(2:,2)
237	kran => ranseeds(2:,3)
238	mran => ranseeds(2:,4)
239	nran => ranseeds(2:,5)
240	ranv = nran
241
242	END IF
243
244	lenran = length
245
246	END SUBROUTINE ran_init
247
248	!------------------------------------------------------------------------------!
249	! Description:
250	! ------------
251	!> User interface to release the workspace used by the random number routines.
252	!------------------------------------------------------------------------------!
253	SUBROUTINE ran_deallocate
254
255	IF ( lenran > 0 ) THEN
256
257	DEALLOCATE(ranseeds, ranv)
258	NULLIFY(ranseeds, ranv, iran, jran, kran, mran, nran)
259	lenran = 0
260
261	END IF
262
263	END SUBROUTINE ran_deallocate
264
265	!------------------------------------------------------------------------------!
266	! Description:
267	! ------------
268	!> User interface for seeding the random number routines.
269	!> Syntax is exactly like Fortran 90's random_seed routine,
270	!> with one additional argument keyword: random_sequence, set to any integer
271	!> value, causes an immediate new initialization, seeded by that integer.
272	!------------------------------------------------------------------------------!
273	SUBROUTINE random_seed_parallel( random_sequence, state_size, put, get )
274
275	IMPLICIT NONE
276
277	INTEGER(isp), OPTIONAL, INTENT(IN) :: random_sequence !<
278	INTEGER(isp), OPTIONAL, INTENT(OUT) :: state_size !<
279
280	INTEGER(isp), DIMENSION(:), OPTIONAL, INTENT(IN) :: put !<
281	INTEGER(isp), DIMENSION(:), OPTIONAL, INTENT(OUT) :: get !<
282
283	IF ( present(state_size) ) THEN
284
285	state_size = 5 * lenran
286
287	ELSE IF ( present(put) ) THEN
288
289	IF ( lenran == 0 ) RETURN
290
291	ranseeds = reshape( put,shape(ranseeds) )
292
293	WHERE (ranseeds(:,1:3) < 0) ranseeds(: ,1:3) = not(ranseeds(: ,1:3))
294	!- Enforce nonnegativity and nonzero conditions on any user-supplied seeds.
295
296	WHERE (ranseeds(:,4:5) == 0) ranseeds(:,4:5) = 1
297
298	iran0 = ranseeds(1,1)
299	jran0 = ranseeds(1,2)
300	kran0 = ranseeds(1,3)
301	mran0 = ranseeds(1,4)
302	nran0 = ranseeds(1,5)
303
304	ELSE IF ( present(get) ) THEN
305
306	IF (lenran == 0) RETURN
307
308	ranseeds(1,1:5) = (/ iran0,jran0,kran0,mran0,nran0 /)
309	get = reshape( ranseeds, shape(get) )
310
311	ELSE IF ( present(random_sequence) ) THEN
312
313	CALL ran_deallocate
314	seq = random_sequence
315
316	END IF
317
318	END SUBROUTINE random_seed_parallel
319
320	!------------------------------------------------------------------------------!
321	! Description:
322	! ------------
323	!> DES-like hashing of two 32-bit integers, using shifts,
324	!> xor's, and adds to make the internal nonlinear function.
325	!------------------------------------------------------------------------------!
326	SUBROUTINE ran_hash_v( il, ir )
327
328	IMPLICIT NONE
329
330	INTEGER(isp), DIMENSION(:), INTENT(INOUT) :: il !<
331	INTEGER(isp), DIMENSION(:), INTENT(INOUT) :: ir !<
332
333	INTEGER(isp), DIMENSION(size(il)) :: is !<
334
335	INTEGER(isp) :: j !<
336
337	DO j=1,4
338
339	is = ir
340	ir = ieor( ir, ishft(ir,5) ) + 1422217823
341	ir = ieor( ir, ishft(ir,-16) ) + 1842055030
342	ir = ieor( ir, ishft(ir,9) ) + 80567781
343	ir = ieor( il, ir )
344	il = is
345	END DO
346
347	END SUBROUTINE ran_hash_v
348
349	!------------------------------------------------------------------------------!
350	! Description:
351	! ------------
352	!> User interface to process error-messages
353	!> produced by the random_number_parallel module
354	!------------------------------------------------------------------------------!
355	SUBROUTINE ran_error(string)
356
357	CHARACTER(LEN=*), INTENT(IN) :: string !<
358
359	write (,) 'Error in module random_number_parallel: ',string
360
361	STOP 'Program terminated by ran_error'
362
363	END SUBROUTINE ran_error
364
365	!------------------------------------------------------------------------------!
366	! Description:
367	! ------------
368	!> Reallocates the generators state space "ranseeds" to vectors of size length.
369	!------------------------------------------------------------------------------!
370	FUNCTION reallocate_iv( p, n )
371
372	INTEGER(isp), DIMENSION(:), POINTER :: p !<
373	INTEGER(isp), DIMENSION(:), POINTER :: reallocate_iv !<
374
375	INTEGER(isp), INTENT(IN) :: n !<
376
377	INTEGER(isp) :: nold !<
378	INTEGER(isp) :: ierr !<
379
380	ALLOCATE(reallocate_iv(n),stat=ierr)
381
382	IF (ierr /= 0) CALL &
383	ran_error('reallocate_iv: problem in attempt to allocate memory')
384
385	IF (.not. associated(p)) RETURN
386
387	nold = size(p)
388
389	reallocate_iv(1:min(nold,n)) = p(1:min(nold,n))
390
391	DEALLOCATE(p)
392
393	END FUNCTION reallocate_iv
394
395	FUNCTION reallocate_im( p, n, m )
396
397	INTEGER(isp), DIMENSION(:,:), POINTER :: p !<
398	INTEGER(isp), DIMENSION(:,:), POINTER :: reallocate_im !<
399
400	INTEGER(isp), INTENT(IN) :: m !<
401	INTEGER(isp), INTENT(IN) :: n !<
402
403	INTEGER(isp) :: mold !<
404	INTEGER(isp) :: nold !<
405	INTEGER(isp) :: ierr !<
406
407	ALLOCATE(reallocate_im(n,m),stat=ierr)
408
409	IF (ierr /= 0) CALL &
410	ran_error('reallocate_im: problem in attempt to allocate memory')
411
412	IF (.not. associated(p)) RETURN
413
414	nold = size(p,1)
415	mold = size(p,2)
416
417	reallocate_im(1:min(nold,n),1:min(mold,m)) = &
418	p(1:min(nold,n),1:min(mold,m))
419
420	DEALLOCATE(p)
421
422	END FUNCTION reallocate_im
423
424	!------------------------------------------------------------------------------!
425	! Description:
426	! ------------
427	!> Reallocates the generators state space "ranseeds" to vectors of size length.
428	!------------------------------------------------------------------------------!
429	FUNCTION arth_i(first,increment,n)
430
431	INTEGER(isp), INTENT(IN) :: first !<
432	INTEGER(isp), INTENT(IN) :: increment !<
433	INTEGER(isp), INTENT(IN) :: n !<
434
435	INTEGER(isp), DIMENSION(n) :: arth_i !<
436
437	INTEGER(isp) :: k !<
438	INTEGER(isp) :: k2 !<
439	INTEGER(isp) :: temp !<
440
441	INTEGER(isp), PARAMETER :: npar_arth=16 !<
442	INTEGER(isp), PARAMETER :: npar2_arth=8 !<
443
444	IF (n > 0) arth_i(1) = first
445
446	IF (n <= npar_arth) THEN
447
448	DO k=2,n
449	arth_i(k) = arth_i(k-1)+increment
450	END DO
451
452	ELSE
453
454	DO k=2,npar2_arth
455	arth_i(k) = arth_i(k-1) + increment
456	END DO
457
458	temp = increment * npar2_arth
459	k = npar2_arth
460
461	DO
462	IF (k >= n) EXIT
463	k2 = k + k
464	arth_i(k+1:min(k2,n)) = temp + arth_i(1:min(k,n-k))
465	temp = temp + temp
466	k = k2
467	END DO
468
469	END IF
470
471	END FUNCTION arth_i
472
473	END MODULE random_generator_parallel

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