Actual source code: randomc.c
petsc-3.12.5 2020-03-29
2: /*
3: This file contains routines for interfacing to random number generators.
4: This provides more than just an interface to some system random number
5: generator:
7: Numbers can be shuffled for use as random tuples
9: Multiple random number generators may be used
11: We are still not sure what interface we want here. There should be
12: one to reinitialize and set the seed.
13: */
15: #include <../src/sys/classes/random/randomimpl.h>
16: #include <petscviewer.h>
18: /* Logging support */
19: PetscClassId PETSC_RANDOM_CLASSID;
21: /*@
22: PetscRandomDestroy - Destroys a context that has been formed by
23: PetscRandomCreate().
25: Collective on PetscRandom
27: Intput Parameter:
28: . r - the random number generator context
30: Level: intermediate
32: .seealso: PetscRandomGetValue(), PetscRandomCreate(), VecSetRandom()
33: @*/
34: PetscErrorCode PetscRandomDestroy(PetscRandom *r)
35: {
39: if (!*r) return(0);
41: if (--((PetscObject)(*r))->refct > 0) {*r = 0; return(0);}
42: if ((*r)->ops->destroy) {
43: (*(*r)->ops->destroy)(*r);
44: }
45: PetscHeaderDestroy(r);
46: return(0);
47: }
50: /*@C
51: PetscRandomGetSeed - Gets the random seed.
53: Not collective
55: Input Parameters:
56: . r - The random number generator context
58: Output Parameter:
59: . seed - The random seed
61: Level: intermediate
63: .seealso: PetscRandomCreate(), PetscRandomSetSeed(), PetscRandomSeed()
64: @*/
65: PetscErrorCode PetscRandomGetSeed(PetscRandom r,unsigned long *seed)
66: {
69: if (seed) {
71: *seed = r->seed;
72: }
73: return(0);
74: }
76: /*@C
77: PetscRandomSetSeed - Sets the random seed. You MUST call PetscRandomSeed() after this call to have the new seed used.
79: Not collective
81: Input Parameters:
82: + r - The random number generator context
83: - seed - The random seed
85: Level: intermediate
87: Usage:
88: PetscRandomSetSeed(r,a positive integer);
89: PetscRandomSeed(r); PetscRandomGetValue() will now start with the new seed.
91: PetscRandomSeed(r) without a call to PetscRandomSetSeed() re-initializes
92: the seed. The random numbers generated will be the same as before.
94: .seealso: PetscRandomCreate(), PetscRandomGetSeed(), PetscRandomSeed()
95: @*/
96: PetscErrorCode PetscRandomSetSeed(PetscRandom r,unsigned long seed)
97: {
102: r->seed = seed;
103: PetscInfo1(NULL,"Setting seed to %d\n",(int)seed);
104: return(0);
105: }
107: /* ------------------------------------------------------------------- */
108: /*
109: PetscRandomSetTypeFromOptions_Private - Sets the type of random generator from user options. Defaults to type PETSCRAND48 or PETSCRAND.
111: Collective on PetscRandom
113: Input Parameter:
114: . rnd - The random number generator context
116: Level: intermediate
118: .seealso: PetscRandomSetFromOptions(), PetscRandomSetType()
119: */
120: static PetscErrorCode PetscRandomSetTypeFromOptions_Private(PetscOptionItems *PetscOptionsObject,PetscRandom rnd)
121: {
122: PetscBool opt;
123: const char *defaultType;
124: char typeName[256];
128: if (((PetscObject)rnd)->type_name) {
129: defaultType = ((PetscObject)rnd)->type_name;
130: } else {
131: defaultType = PETSCRANDER48;
132: }
134: PetscRandomRegisterAll();
135: PetscOptionsFList("-random_type","PetscRandom type","PetscRandomSetType",PetscRandomList,defaultType,typeName,256,&opt);
136: if (opt) {
137: PetscRandomSetType(rnd, typeName);
138: } else {
139: PetscRandomSetType(rnd, defaultType);
140: }
141: return(0);
142: }
144: /*@
145: PetscRandomSetFromOptions - Configures the random number generator from the options database.
147: Collective on PetscRandom
149: Input Parameter:
150: . rnd - The random number generator context
152: Options Database:
153: + -random_seed <integer> - provide a seed to the random number generater
154: - -random_no_imaginary_part - makes the imaginary part of the random number zero, this is useful when you want the
155: same code to produce the same result when run with real numbers or complex numbers for regression testing purposes
157: Notes:
158: To see all options, run your program with the -help option.
159: Must be called after PetscRandomCreate() but before the rnd is used.
161: Level: beginner
163: .seealso: PetscRandomCreate(), PetscRandomSetType()
164: @*/
165: PetscErrorCode PetscRandomSetFromOptions(PetscRandom rnd)
166: {
168: PetscBool set,noimaginary = PETSC_FALSE;
169: PetscInt seed;
174: PetscObjectOptionsBegin((PetscObject)rnd);
176: /* Handle PetscRandom type options */
177: PetscRandomSetTypeFromOptions_Private(PetscOptionsObject,rnd);
179: /* Handle specific random generator's options */
180: if (rnd->ops->setfromoptions) {
181: (*rnd->ops->setfromoptions)(PetscOptionsObject,rnd);
182: }
183: PetscOptionsInt("-random_seed","Seed to use to generate random numbers","PetscRandomSetSeed",0,&seed,&set);
184: if (set) {
185: PetscRandomSetSeed(rnd,(unsigned long int)seed);
186: PetscRandomSeed(rnd);
187: }
188: PetscOptionsBool("-random_no_imaginary_part","The imaginary part of the random number will be zero","PetscRandomSetInterval",noimaginary,&noimaginary,&set);
189: #if defined(PETSC_HAVE_COMPLEX)
190: if (set) {
191: if (noimaginary) {
192: PetscScalar low,high;
193: PetscRandomGetInterval(rnd,&low,&high);
194: low = low - PetscImaginaryPart(low);
195: high = high - PetscImaginaryPart(high);
196: PetscRandomSetInterval(rnd,low,high);
197: }
198: }
199: #endif
200: PetscOptionsEnd();
201: PetscRandomViewFromOptions(rnd,NULL, "-random_view");
202: return(0);
203: }
205: #if defined(PETSC_HAVE_SAWS)
206: #include <petscviewersaws.h>
207: #endif
208: /*@C
209: PetscRandomView - Views a random number generator object.
211: Collective on PetscRandom
213: Input Parameters:
214: + rnd - The random number generator context
215: - viewer - an optional visualization context
217: Notes:
218: The available visualization contexts include
219: + PETSC_VIEWER_STDOUT_SELF - standard output (default)
220: - PETSC_VIEWER_STDOUT_WORLD - synchronized standard
221: output where only the first processor opens
222: the file. All other processors send their
223: data to the first processor to print.
225: You can change the format the vector is printed using the
226: option PetscViewerPushFormat().
228: Level: beginner
230: .seealso: PetscRealView(), PetscScalarView(), PetscIntView()
231: @*/
232: PetscErrorCode PetscRandomView(PetscRandom rnd,PetscViewer viewer)
233: {
235: PetscBool iascii;
236: #if defined(PETSC_HAVE_SAWS)
237: PetscBool issaws;
238: #endif
243: if (!viewer) {
244: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)rnd),&viewer);
245: }
248: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
249: #if defined(PETSC_HAVE_SAWS)
250: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&issaws);
251: #endif
252: if (iascii) {
253: PetscMPIInt rank;
254: PetscObjectPrintClassNamePrefixType((PetscObject)rnd,viewer);
255: MPI_Comm_rank(PetscObjectComm((PetscObject)rnd),&rank);
256: PetscViewerASCIIPushSynchronized(viewer);
257: PetscViewerASCIISynchronizedPrintf(viewer,"[%d] Random type %s, seed %lu\n",rank,((PetscObject)rnd)->type_name,rnd->seed);
258: PetscViewerFlush(viewer);
259: PetscViewerASCIIPopSynchronized(viewer);
260: #if defined(PETSC_HAVE_SAWS)
261: } else if (issaws) {
262: PetscMPIInt rank;
263: const char *name;
265: PetscObjectGetName((PetscObject)rnd,&name);
266: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
267: if (!((PetscObject)rnd)->amsmem && !rank) {
268: char dir[1024];
270: PetscObjectViewSAWs((PetscObject)rnd,viewer);
271: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/Low",name);
272: PetscStackCallSAWs(SAWs_Register,(dir,&rnd->low,1,SAWs_READ,SAWs_DOUBLE));
273: }
274: #endif
275: }
276: return(0);
277: }
279: /*@
280: PetscRandomCreate - Creates a context for generating random numbers,
281: and initializes the random-number generator.
283: Collective
285: Input Parameters:
286: . comm - MPI communicator
288: Output Parameter:
289: . r - the random number generator context
291: Level: intermediate
293: Notes:
294: The random type has to be set by PetscRandomSetType().
296: This is only a primative "parallel" random number generator, it should NOT
297: be used for sophisticated parallel Monte Carlo methods since it will very likely
298: not have the correct statistics across processors. You can provide your own
299: parallel generator using PetscRandomRegister();
301: If you create a PetscRandom() using PETSC_COMM_SELF on several processors then
302: the SAME random numbers will be generated on all those processors. Use PETSC_COMM_WORLD
303: or the appropriate parallel communicator to eliminate this issue.
305: Use VecSetRandom() to set the elements of a vector to random numbers.
307: Example of Usage:
308: .vb
309: PetscRandomCreate(PETSC_COMM_SELF,&r);
310: PetscRandomSetType(r,PETSCRAND48);
311: PetscRandomGetValue(r,&value1);
312: PetscRandomGetValueReal(r,&value2);
313: PetscRandomDestroy(&r);
314: .ve
316: .seealso: PetscRandomSetType(), PetscRandomGetValue(), PetscRandomGetValueReal(), PetscRandomSetInterval(),
317: PetscRandomDestroy(), VecSetRandom(), PetscRandomType
318: @*/
320: PetscErrorCode PetscRandomCreate(MPI_Comm comm,PetscRandom *r)
321: {
322: PetscRandom rr;
324: PetscMPIInt rank;
328: *r = NULL;
329: PetscRandomInitializePackage();
331: PetscHeaderCreate(rr,PETSC_RANDOM_CLASSID,"PetscRandom","Random number generator","Sys",comm,PetscRandomDestroy,PetscRandomView);
333: MPI_Comm_rank(comm,&rank);
335: rr->data = NULL;
336: rr->low = 0.0;
337: rr->width = 1.0;
338: rr->iset = PETSC_FALSE;
339: rr->seed = 0x12345678 + 76543*rank;
340: PetscRandomSetType(rr,PETSCRANDER48);
341: *r = rr;
342: return(0);
343: }
345: /*@
346: PetscRandomSeed - Seed the generator.
348: Not collective
350: Input Parameters:
351: . r - The random number generator context
353: Level: intermediate
355: Usage:
356: PetscRandomSetSeed(r,a positive integer);
357: PetscRandomSeed(r); PetscRandomGetValue() will now start with the new seed.
359: PetscRandomSeed(r) without a call to PetscRandomSetSeed() re-initializes
360: the seed. The random numbers generated will be the same as before.
362: .seealso: PetscRandomCreate(), PetscRandomGetSeed(), PetscRandomSetSeed()
363: @*/
364: PetscErrorCode PetscRandomSeed(PetscRandom r)
365: {
372: (*r->ops->seed)(r);
373: PetscObjectStateIncrease((PetscObject)r);
374: return(0);
375: }