Home

Context Navigation

source: palm/trunk/SOURCE/random_generator_parallel_mod.f90 @ 2035

Last change on this file since 2035 was 2001, checked in by knoop, 8 years ago
last commit documented
Property svn:keywords set to `Id`
File size: 16.3 KB

Line
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
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 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 1997-2016 Leibniz Universitaet Hannover
18	!------------------------------------------------------------------------------!
19	!
20	! Current revisions:
21	! -----------------
22	!
23	!
24	! Former revisions:
25	! -----------------
26	! $Id: random_generator_parallel_mod.f90 2001 2016-08-20 18:41:22Z suehring $
27	!
28	! 2000 2016-08-20 18:09:15Z knoop
29	! Forced header and separation lines into 80 columns
30	!
31	! 1850 2016-04-08 13:29:27Z maronga
32	! Module renamed
33	!
34	!
35	! 1682 2015-10-07 23:56:08Z knoop
36	! Code annotations made doxygen readable
37	!
38	! 1400 2014-05-09 14:03:54Z knoop
39	! Initial revision
40	!
41	!
42	! Description:
43	! ------------
44	!> This module contains and supports the random number generating routine ran_parallel.
45	!> ran_parallel returns a uniform random deviate between 0.0 and 1.0
46	!> (exclusive of the end point values).
47	!> Additionally it provides the generator with five integer for use as initial state space.
48	!> The first tree integers (iran, jran, kran) are maintained as non negative values,
49	!> while the last two (mran, nran) have 32-bit nonzero values.
50	!> Also provided by this module is support for initializing or reinitializing
51	!> the state space to a desired standard sequence number, hashing the initial
52	!> values to random values, and allocating and deallocating the internal workspace
53	!> Random number generator, produces numbers equally distributed in interval
54	!>
55	!> This routine is taken from the "numerical recipies vol. 2"
56	!------------------------------------------------------------------------------!
57	MODULE random_generator_parallel
58
59
60	USE kinds
61
62	IMPLICIT NONE
63
64	PRIVATE
65	PUBLIC random_number_parallel, random_seed_parallel, random_dummy, &
66	id_random_array, seq_random_array
67
68	INTEGER(isp), SAVE :: lenran=0 !<
69	INTEGER(isp), SAVE :: seq=0 !<
70	INTEGER(isp), SAVE :: iran0 !<
71	INTEGER(isp), SAVE :: jran0 !<
72	INTEGER(isp), SAVE :: kran0 !<
73	INTEGER(isp), SAVE :: mran0 !<
74	INTEGER(isp), SAVE :: nran0 !<
75	INTEGER(isp), SAVE :: rans !<
76
77	INTEGER(isp), DIMENSION(:, :), POINTER, SAVE :: ranseeds !<
78
79	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: iran !<
80	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: jran !<
81	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: kran !<
82	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: mran !<
83	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: nran !<
84	INTEGER(isp), DIMENSION(:), POINTER, SAVE :: ranv !<
85
86
87
88	INTEGER(isp), DIMENSION(:,:), ALLOCATABLE :: id_random_array !<
89	INTEGER(isp), DIMENSION(:,:,:), ALLOCATABLE :: seq_random_array !<
90
91	REAL(wp), SAVE :: amm !<
92
93	REAL(wp) :: random_dummy=0.0 !<
94
95	INTERFACE random_number_parallel
96	MODULE PROCEDURE ran0_s
97	END INTERFACE
98
99	INTERFACE random_seed_parallel
100	MODULE PROCEDURE random_seed_parallel
101	END INTERFACE
102
103	INTERFACE ran_hash
104	MODULE PROCEDURE ran_hash_v
105	END INTERFACE
106
107	INTERFACE reallocate
108	MODULE PROCEDURE reallocate_iv,reallocate_im
109	END INTERFACE
110
111	INTERFACE arth
112	MODULE PROCEDURE arth_i
113	END INTERFACE
114
115	CONTAINS
116
117	!------------------------------------------------------------------------------!
118	! Description:
119	! ------------
120	!> Lagged Fibonacci generator combined with a Marsaglia shiftsequence.
121	!> Returns as harvest a uniform random deviate between 0.0 and 1.0 (exclusive of the end point values).
122	!> This generator has the same calling and initialization conventions as Fortran 90's random_number routine.
123	!> Use random_seed_parallel to initialize or reinitialize to a particular sequence.
124	!> The period of this generator is about 2.0 x 10^28, and it fully vectorizes.
125	!> Validity of the integer model assumed by this generator is tested at initialization.
126	!------------------------------------------------------------------------------!
127	SUBROUTINE ran0_s(harvest)
128
129	USE kinds
130
131	IMPLICIT NONE
132
133	REAL(wp), INTENT(OUT) :: harvest !<
134
135	IF (lenran < 1) CALL ran_init(1) !- Initialization routine in ran_state.
136
137	!- Update Fibonacci generator, which has period p^2 + p + 1, p = 2^31 - 69.
138	rans = iran0 - kran0
139
140	IF (rans < 0) rans = rans + 2147483579_isp
141
142	iran0 = jran0
143	jran0 = kran0
144	kran0 = rans
145
146	nran0 = ieor( nran0, ishft (nran0, 13) ) !- Update Marsaglia shift sequence with period 2^32 - 1.
147	nran0 = ieor( nran0, ishft (nran0, -17) )
148	nran0 = ieor( nran0, ishft (nran0, 5) )
149
150	rans = ieor( nran0, rans ) !- Combine the generators.
151
152	harvest = amm * merge( rans, not(rans), rans < 0 ) !- Make the result positive definite (note that amm is negative).
153
154	END SUBROUTINE ran0_s
155
156	!------------------------------------------------------------------------------!
157	! Description:
158	! ------------
159	!> Initialize or reinitialize the random generator state space to vectors of size length.
160	!> The saved variable seq is hashed (via calls to the module routine ran_hash)
161	!> to create unique starting seeds, different for each vector component.
162	!------------------------------------------------------------------------------!
163	SUBROUTINE ran_init( length )
164
165	USE kinds
166
167	IMPLICIT NONE
168
169	INTEGER(isp), INTENT(IN) :: length !<
170
171	INTEGER(isp), PARAMETER:: hg=huge(1_isp) !<
172	INTEGER(isp), PARAMETER:: hgm=-hg !<
173	INTEGER(isp), PARAMETER:: hgng=hgm-1 !<
174
175	INTEGER(isp) :: new !<
176	INTEGER(isp) :: j !<
177	INTEGER(isp) :: hgt !<
178
179	IF ( length < lenran ) RETURN !- Simply return if enough space is already allocated.
180
181	hgt = hg
182
183	!- The following lines check that kind value isp is in fact a 32-bit integer
184	!- with the usual properties that we expect it to have (under negation and wrap-around addition).
185	!- If all of these tests are satisfied, then the routines that use this module are portable,
186	!- even though they go beyond Fortran 90's integer model.
187
188	IF ( hg /= 2147483647 ) CALL ran_error('ran_init: arith assump 1 fails')
189	IF ( hgng >= 0 ) CALL ran_error('ran_init: arith assump 2 fails')
190	IF ( hgt+1 /= hgng ) CALL ran_error('ran_init: arith assump 3 fails')
191	IF ( not(hg) >= 0 ) CALL ran_error('ran_init: arith assump 4 fails')
192	IF ( not(hgng) < 0 ) CALL ran_error('ran_init: arith assump 5 fails')
193	IF ( hg+hgng >= 0 ) CALL ran_error('ran_init: arith assump 6 fails')
194	IF ( not(-1_isp) < 0 ) CALL ran_error('ran_init: arith assump 7 fails')
195	IF ( not(0_isp) >= 0 ) CALL ran_error('ran_init: arith assump 8 fails')
196	IF ( not(1_isp) >= 0 ) CALL ran_error('ran_init: arith assump 9 fails')
197
198	IF ( lenran > 0) THEN !- Reallocate space, or ...
199
200	ranseeds => reallocate( ranseeds, length, 5)
201	ranv => reallocate( ranv, length-1)
202	new = lenran+1
203
204	ELSE !- allocate space.
205
206	ALLOCATE(ranseeds(length,5))
207	ALLOCATE(ranv(length-1))
208	new = 1 !- Index of first location not yet initialized.
209	amm = nearest(1.0_wp,-1.0_wp)/hgng
210	!- Use of nearest is to ensure that returned random deviates are strictly lessthan 1.0.
211	IF (ammhgng >= 1.0 .or. ammhgng <= 0.0) &
212	CALL ran_error('ran_init: arith assump 10 fails')
213
214	END IF
215
216	!- Set starting values, unique by seq and vector component.
217	ranseeds(new:,1) = seq
218	ranseeds(new:,2:5)=spread(arth(new,1,size(ranseeds(new:,1))),2,4)
219
220	DO j=1,4 !- Hash them.
221	CALL ran_hash(ranseeds(new:,j), ranseeds(new:,j+1))
222	END DO
223
224	WHERE (ranseeds (new: ,1:3) < 0) &
225	ranseeds(new: ,1:3)=not(ranseeds(new: ,1:3)) !- Enforce nonnegativity.
226
227	WHERE (ranseeds(new: ,4:5) == 0) ranseeds(new: ,4:5)=1 !- Enforce nonzero.
228
229	IF (new == 1) THEN !- Set scalar seeds.
230
231	iran0 = ranseeds(1,1)
232	jran0 = ranseeds(1,2)
233	kran0 = ranseeds(1,3)
234	mran0 = ranseeds(1,4)
235	nran0 = ranseeds(1,5)
236	rans = nran0
237
238	END IF
239
240	IF (length > 1) THEN !- Point to vector seeds.
241
242	iran => ranseeds(2:,1)
243	jran => ranseeds(2:,2)
244	kran => ranseeds(2:,3)
245	mran => ranseeds(2:,4)
246	nran => ranseeds(2:,5)
247	ranv = nran
248
249	END IF
250
251	lenran = length
252
253	END SUBROUTINE ran_init
254
255	!------------------------------------------------------------------------------!
256	! Description:
257	! ------------
258	!> User interface to release the workspace used by the random number routines.
259	!------------------------------------------------------------------------------!
260	SUBROUTINE ran_deallocate
261
262	IF ( lenran > 0 ) THEN
263
264	DEALLOCATE(ranseeds, ranv)
265	NULLIFY(ranseeds, ranv, iran, jran, kran, mran, nran)
266	lenran = 0
267
268	END IF
269
270	END SUBROUTINE ran_deallocate
271
272	!------------------------------------------------------------------------------!
273	! Description:
274	! ------------
275	!> User interface for seeding the random number routines.
276	!> Syntax is exactly like Fortran 90's random_seed routine,
277	!> with one additional argument keyword: random_sequence, set to any integer
278	!> value, causes an immediate new initialization, seeded by that integer.
279	!------------------------------------------------------------------------------!
280	SUBROUTINE random_seed_parallel( random_sequence, state_size, put, get )
281
282	IMPLICIT NONE
283
284	INTEGER(isp), OPTIONAL, INTENT(IN) :: random_sequence !<
285	INTEGER(isp), OPTIONAL, INTENT(OUT) :: state_size !<
286
287	INTEGER(isp), DIMENSION(:), OPTIONAL, INTENT(IN) :: put !<
288	INTEGER(isp), DIMENSION(:), OPTIONAL, INTENT(OUT) :: get !<
289
290	IF ( present(state_size) ) THEN
291
292	state_size = 5 * lenran
293
294	ELSE IF ( present(put) ) THEN
295
296	IF ( lenran == 0 ) RETURN
297
298	ranseeds = reshape( put,shape(ranseeds) )
299
300	WHERE (ranseeds(:,1:3) < 0) ranseeds(: ,1:3) = not(ranseeds(: ,1:3))
301	!- Enforce nonnegativity and nonzero conditions on any user-supplied seeds.
302
303	WHERE (ranseeds(:,4:5) == 0) ranseeds(:,4:5) = 1
304
305	iran0 = ranseeds(1,1)
306	jran0 = ranseeds(1,2)
307	kran0 = ranseeds(1,3)
308	mran0 = ranseeds(1,4)
309	nran0 = ranseeds(1,5)
310
311	ELSE IF ( present(get) ) THEN
312
313	IF (lenran == 0) RETURN
314
315	ranseeds(1,1:5) = (/ iran0,jran0,kran0,mran0,nran0 /)
316	get = reshape( ranseeds, shape(get) )
317
318	ELSE IF ( present(random_sequence) ) THEN
319
320	CALL ran_deallocate
321	seq = random_sequence
322
323	END IF
324
325	END SUBROUTINE random_seed_parallel
326
327	!------------------------------------------------------------------------------!
328	! Description:
329	! ------------
330	!> DES-like hashing of two 32-bit integers, using shifts,
331	!> xor's, and adds to make the internal nonlinear function.
332	!------------------------------------------------------------------------------!
333	SUBROUTINE ran_hash_v( il, ir )
334
335	IMPLICIT NONE
336
337	INTEGER(isp), DIMENSION(:), INTENT(INOUT) :: il !<
338	INTEGER(isp), DIMENSION(:), INTENT(INOUT) :: ir !<
339
340	INTEGER(isp), DIMENSION(size(il)) :: is !<
341
342	INTEGER(isp) :: j !<
343
344	DO j=1,4
345
346	is = ir
347	ir = ieor( ir, ishft(ir,5) ) + 1422217823
348	ir = ieor( ir, ishft(ir,-16) ) + 1842055030
349	ir = ieor( ir, ishft(ir,9) ) + 80567781
350	ir = ieor( il, ir )
351	il = is
352	END DO
353
354	END SUBROUTINE ran_hash_v
355
356	!------------------------------------------------------------------------------!
357	! Description:
358	! ------------
359	!> User interface to process error-messages
360	!> produced by the random_number_parallel module
361	!------------------------------------------------------------------------------!
362	SUBROUTINE ran_error(string)
363
364	CHARACTER(LEN=*), INTENT(IN) :: string !<
365
366	write (,) 'Error in module random_number_parallel: ',string
367
368	STOP 'Program terminated by ran_error'
369
370	END SUBROUTINE ran_error
371
372	!------------------------------------------------------------------------------!
373	! Description:
374	! ------------
375	!> Reallocates the generators state space "ranseeds" to vectors of size length.
376	!------------------------------------------------------------------------------!
377	FUNCTION reallocate_iv( p, n )
378
379	INTEGER(isp), DIMENSION(:), POINTER :: p !<
380	INTEGER(isp), DIMENSION(:), POINTER :: reallocate_iv !<
381
382	INTEGER(isp), INTENT(IN) :: n !<
383
384	INTEGER(isp) :: nold !<
385	INTEGER(isp) :: ierr !<
386
387	ALLOCATE(reallocate_iv(n),stat=ierr)
388
389	IF (ierr /= 0) CALL &
390	ran_error('reallocate_iv: problem in attempt to allocate memory')
391
392	IF (.not. associated(p)) RETURN
393
394	nold = size(p)
395
396	reallocate_iv(1:min(nold,n)) = p(1:min(nold,n))
397
398	DEALLOCATE(p)
399
400	END FUNCTION reallocate_iv
401
402	FUNCTION reallocate_im( p, n, m )
403
404	INTEGER(isp), DIMENSION(:,:), POINTER :: p !<
405	INTEGER(isp), DIMENSION(:,:), POINTER :: reallocate_im !<
406
407	INTEGER(isp), INTENT(IN) :: m !<
408	INTEGER(isp), INTENT(IN) :: n !<
409
410	INTEGER(isp) :: mold !<
411	INTEGER(isp) :: nold !<
412	INTEGER(isp) :: ierr !<
413
414	ALLOCATE(reallocate_im(n,m),stat=ierr)
415
416	IF (ierr /= 0) CALL &
417	ran_error('reallocate_im: problem in attempt to allocate memory')
418
419	IF (.not. associated(p)) RETURN
420
421	nold = size(p,1)
422	mold = size(p,2)
423
424	reallocate_im(1:min(nold,n),1:min(mold,m)) = &
425	p(1:min(nold,n),1:min(mold,m))
426
427	DEALLOCATE(p)
428
429	END FUNCTION reallocate_im
430
431	!------------------------------------------------------------------------------!
432	! Description:
433	! ------------
434	!> Reallocates the generators state space "ranseeds" to vectors of size length.
435	!------------------------------------------------------------------------------!
436	FUNCTION arth_i(first,increment,n)
437
438	INTEGER(isp), INTENT(IN) :: first !<
439	INTEGER(isp), INTENT(IN) :: increment !<
440	INTEGER(isp), INTENT(IN) :: n !<
441
442	INTEGER(isp), DIMENSION(n) :: arth_i !<
443
444	INTEGER(isp) :: k !<
445	INTEGER(isp) :: k2 !<
446	INTEGER(isp) :: temp !<
447
448	INTEGER(isp), PARAMETER :: npar_arth=16 !<
449	INTEGER(isp), PARAMETER :: npar2_arth=8 !<
450
451	IF (n > 0) arth_i(1) = first
452
453	IF (n <= npar_arth) THEN
454
455	DO k=2,n
456	arth_i(k) = arth_i(k-1)+increment
457	END DO
458
459	ELSE
460
461	DO k=2,npar2_arth
462	arth_i(k) = arth_i(k-1) + increment
463	END DO
464
465	temp = increment * npar2_arth
466	k = npar2_arth
467
468	DO
469	IF (k >= n) EXIT
470	k2 = k + k
471	arth_i(k+1:min(k2,n)) = temp + arth_i(1:min(k,n-k))
472	temp = temp + temp
473	k = k2
474	END DO
475
476	END IF
477
478	END FUNCTION arth_i
479
480	END MODULE random_generator_parallel

Note: See TracBrowser for help on using the repository browser.

Download in other formats:

| Impressum | ©Leibniz Universität Hannover |