1 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: 6 7 Numbers can be shuffled for use as random tuples 8 9 Multiple random number generators may be used 10 11 We are still not sure what interface we want here. There should be 12 one to reinitialize and set the seed. 13 */ 14 15 #include <../src/sys/classes/random/randomimpl.h> /*I "petscsys.h" I*/ 16 #include <petscviewer.h> 17 18 /* Logging support */ 19 PetscClassId PETSC_RANDOM_CLASSID; 20 21 #undef __FUNCT__ 22 #define __FUNCT__ "PetscRandomDestroy" 23 /*@ 24 PetscRandomDestroy - Destroys a context that has been formed by 25 PetscRandomCreate(). 26 27 Collective on PetscRandom 28 29 Intput Parameter: 30 . r - the random number generator context 31 32 Level: intermediate 33 34 .seealso: PetscRandomGetValue(), PetscRandomCreate(), VecSetRandom() 35 @*/ 36 PetscErrorCode PetscRandomDestroy(PetscRandom *r) 37 { 38 PetscErrorCode ierr; 39 40 PetscFunctionBegin; 41 if (!*r) PetscFunctionReturn(0); 42 PetscValidHeaderSpecific(*r,PETSC_RANDOM_CLASSID,1); 43 if (--((PetscObject)(*r))->refct > 0) {*r = 0; PetscFunctionReturn(0);} 44 ierr = PetscHeaderDestroy(r);CHKERRQ(ierr); 45 PetscFunctionReturn(0); 46 } 47 48 49 #undef __FUNCT__ 50 #define __FUNCT__ "PetscRandomGetSeed" 51 /*@ 52 PetscRandomGetSeed - Gets the random seed. 53 54 Not collective 55 56 Input Parameters: 57 . r - The random number generator context 58 59 Output Parameter: 60 . seed - The random seed 61 62 Level: intermediate 63 64 Concepts: random numbers^seed 65 66 .seealso: PetscRandomCreate(), PetscRandomSetSeed(), PetscRandomSeed() 67 @*/ 68 PetscErrorCode PetscRandomGetSeed(PetscRandom r,unsigned long *seed) 69 { 70 PetscFunctionBegin; 71 PetscValidHeaderSpecific(r,PETSC_RANDOM_CLASSID,1); 72 if (seed) { 73 PetscValidPointer(seed,2); 74 *seed = r->seed; 75 } 76 PetscFunctionReturn(0); 77 } 78 79 #undef __FUNCT__ 80 #define __FUNCT__ "PetscRandomSetSeed" 81 /*@ 82 PetscRandomSetSeed - Sets the random seed. You MUST call PetscRandomSeed() after this call to have the new seed used. 83 84 Not collective 85 86 Input Parameters: 87 + r - The random number generator context 88 - seed - The random seed 89 90 Level: intermediate 91 92 Usage: 93 PetscRandomSetSeed(r,a positive integer); 94 PetscRandomSeed(r); PetscRandomGetValue() will now start with the new seed. 95 96 PetscRandomSeed(r) without a call to PetscRandomSetSeed() re-initializes 97 the seed. The random numbers generated will be the same as before. 98 99 Concepts: random numbers^seed 100 101 .seealso: PetscRandomCreate(), PetscRandomGetSeed(), PetscRandomSeed() 102 @*/ 103 PetscErrorCode PetscRandomSetSeed(PetscRandom r,unsigned long seed) 104 { 105 PetscErrorCode ierr; 106 107 PetscFunctionBegin; 108 PetscValidHeaderSpecific(r,PETSC_RANDOM_CLASSID,1); 109 r->seed = seed; 110 ierr = PetscInfo1(NULL,"Setting seed to %d\n",(int)seed);CHKERRQ(ierr); 111 PetscFunctionReturn(0); 112 } 113 114 /* ------------------------------------------------------------------- */ 115 #undef __FUNCT__ 116 #define __FUNCT__ "PetscRandomSetTypeFromOptions_Private" 117 /* 118 PetscRandomSetTypeFromOptions_Private - Sets the type of random generator from user options. Defaults to type PETSCRAND48 or PETSCRAND. 119 120 Collective on PetscRandom 121 122 Input Parameter: 123 . rnd - The random number generator context 124 125 Level: intermediate 126 127 .keywords: PetscRandom, set, options, database, type 128 .seealso: PetscRandomSetFromOptions(), PetscRandomSetType() 129 */ 130 static PetscErrorCode PetscRandomSetTypeFromOptions_Private(PetscRandom rnd) 131 { 132 PetscBool opt; 133 const char *defaultType; 134 char typeName[256]; 135 PetscErrorCode ierr; 136 137 PetscFunctionBegin; 138 if (((PetscObject)rnd)->type_name) { 139 defaultType = ((PetscObject)rnd)->type_name; 140 } else { 141 #if defined(PETSC_HAVE_DRAND48) 142 defaultType = PETSCRAND48; 143 #elif defined(PETSC_HAVE_RAND) 144 defaultType = PETSCRAND; 145 #endif 146 } 147 148 if (!PetscRandomRegisterAllCalled) {ierr = PetscRandomRegisterAll();CHKERRQ(ierr);} 149 ierr = PetscOptionsList("-random_type","PetscRandom type","PetscRandomSetType",PetscRandomList,defaultType,typeName,256,&opt);CHKERRQ(ierr); 150 if (opt) { 151 ierr = PetscRandomSetType(rnd, typeName);CHKERRQ(ierr); 152 } else { 153 ierr = PetscRandomSetType(rnd, defaultType);CHKERRQ(ierr); 154 } 155 PetscFunctionReturn(0); 156 } 157 158 #undef __FUNCT__ 159 #define __FUNCT__ "PetscRandomSetFromOptions" 160 /*@ 161 PetscRandomSetFromOptions - Configures the random number generator from the options database. 162 163 Collective on PetscRandom 164 165 Input Parameter: 166 . rnd - The random number generator context 167 168 Options Database: 169 . -random_seed <integer> - provide a seed to the random number generater 170 171 Notes: To see all options, run your program with the -help option. 172 Must be called after PetscRandomCreate() but before the rnd is used. 173 174 Level: beginner 175 176 .keywords: PetscRandom, set, options, database 177 .seealso: PetscRandomCreate(), PetscRandomSetType() 178 @*/ 179 PetscErrorCode PetscRandomSetFromOptions(PetscRandom rnd) 180 { 181 PetscErrorCode ierr; 182 PetscBool set; 183 PetscInt seed; 184 185 PetscFunctionBegin; 186 PetscValidHeaderSpecific(rnd,PETSC_RANDOM_CLASSID,1); 187 188 ierr = PetscObjectOptionsBegin((PetscObject)rnd);CHKERRQ(ierr); 189 190 /* Handle PetscRandom type options */ 191 ierr = PetscRandomSetTypeFromOptions_Private(rnd);CHKERRQ(ierr); 192 193 /* Handle specific random generator's options */ 194 if (rnd->ops->setfromoptions) { 195 ierr = (*rnd->ops->setfromoptions)(rnd);CHKERRQ(ierr); 196 } 197 ierr = PetscOptionsInt("-random_seed","Seed to use to generate random numbers","PetscRandomSetSeed",0,&seed,&set);CHKERRQ(ierr); 198 if (set) { 199 ierr = PetscRandomSetSeed(rnd,(unsigned long int)seed);CHKERRQ(ierr); 200 ierr = PetscRandomSeed(rnd);CHKERRQ(ierr); 201 } 202 ierr = PetscOptionsEnd();CHKERRQ(ierr); 203 ierr = PetscRandomViewFromOptions(rnd,NULL, "-random_view");CHKERRQ(ierr); 204 PetscFunctionReturn(0); 205 } 206 207 #if defined(PETSC_HAVE_SAWS) 208 #include <petscviewersaws.h> 209 #endif 210 #undef __FUNCT__ 211 #define __FUNCT__ "PetscRandomView" 212 /*@C 213 PetscRandomView - Views a random number generator object. 214 215 Collective on PetscRandom 216 217 Input Parameters: 218 + rnd - The random number generator context 219 - viewer - an optional visualization context 220 221 Notes: 222 The available visualization contexts include 223 + PETSC_VIEWER_STDOUT_SELF - standard output (default) 224 - PETSC_VIEWER_STDOUT_WORLD - synchronized standard 225 output where only the first processor opens 226 the file. All other processors send their 227 data to the first processor to print. 228 229 You can change the format the vector is printed using the 230 option PetscViewerSetFormat(). 231 232 Level: beginner 233 234 .seealso: PetscRealView(), PetscScalarView(), PetscIntView() 235 @*/ 236 PetscErrorCode PetscRandomView(PetscRandom rnd,PetscViewer viewer) 237 { 238 PetscErrorCode ierr; 239 PetscBool iascii; 240 #if defined(PETSC_HAVE_SAWS) 241 PetscBool isams; 242 #endif 243 244 PetscFunctionBegin; 245 PetscValidHeaderSpecific(rnd,PETSC_RANDOM_CLASSID,1); 246 PetscValidType(rnd,1); 247 if (!viewer) { 248 ierr = PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)rnd),&viewer);CHKERRQ(ierr); 249 } 250 PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,2); 251 PetscCheckSameComm(rnd,1,viewer,2); 252 ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr); 253 #if defined(PETSC_HAVE_SAWS) 254 ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&isams);CHKERRQ(ierr); 255 #endif 256 if (iascii) { 257 PetscMPIInt rank; 258 ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)rnd),&rank);CHKERRQ(ierr); 259 ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_TRUE);CHKERRQ(ierr); 260 ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%D] Random type %s, seed %D\n",rank,((PetscObject)rnd)->type_name,rnd->seed);CHKERRQ(ierr); 261 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 262 ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_FALSE);CHKERRQ(ierr); 263 #if defined(PETSC_HAVE_SAWS) 264 } else if (isams) { 265 if (!((PetscObject)rnd)->amsmem) { 266 char dir[1024]; 267 const char *name; 268 ierr = PetscObjectGetName((PetscObject)rnd,&name);CHKERRQ(ierr); 269 ierr = PetscObjectViewSAWs((PetscObject)rnd,viewer);CHKERRQ(ierr); 270 ierr = PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/Low",name);CHKERRQ(ierr); 271 PetscStackCallSAWs(SAWs_Register,(dir,&rnd->low,1,SAWs_READ,SAWs_DOUBLE)); 272 } 273 #endif 274 } 275 PetscFunctionReturn(0); 276 } 277 278 #undef __FUNCT__ 279 #define __FUNCT__ "PetscRandomViewFromOptions" 280 /* 281 PetscRandomViewFromOptions - This function visualizes the type and the seed of the generated random numbers based upon user options. 282 283 Collective on PetscRandom 284 285 Input Parameters: 286 + rnd - The random number generator context 287 . prefix - prefix to use for viewing, or NULL to use prefix of 'rnd' 288 - optionname - option to activate viewing 289 290 Level: intermediate 291 292 .keywords: PetscRandom, view, options, database 293 .seealso: PetscRandomSetFromOptions() 294 */ 295 PetscErrorCode PetscRandomViewFromOptions(PetscRandom rnd, const char prefix[], const char optionname[]) 296 { 297 PetscBool flg; 298 PetscViewer viewer; 299 PetscErrorCode ierr; 300 PetscViewerFormat format; 301 302 PetscFunctionBegin; 303 if (prefix) { 304 ierr = PetscOptionsGetViewer(PetscObjectComm((PetscObject)rnd),prefix,optionname,&viewer,&format,&flg);CHKERRQ(ierr); 305 } else { 306 ierr = PetscOptionsGetViewer(PetscObjectComm((PetscObject)rnd),((PetscObject)rnd)->prefix,optionname,&viewer,&format,&flg);CHKERRQ(ierr); 307 } 308 if (flg) { 309 ierr = PetscViewerPushFormat(viewer,format);CHKERRQ(ierr); 310 ierr = PetscRandomView(rnd,viewer);CHKERRQ(ierr); 311 ierr = PetscViewerPopFormat(viewer);CHKERRQ(ierr); 312 ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr); 313 } 314 PetscFunctionReturn(0); 315 } 316 317 #undef __FUNCT__ 318 #define __FUNCT__ "PetscRandomCreate" 319 /*@ 320 PetscRandomCreate - Creates a context for generating random numbers, 321 and initializes the random-number generator. 322 323 Collective on MPI_Comm 324 325 Input Parameters: 326 + comm - MPI communicator 327 328 Output Parameter: 329 . r - the random number generator context 330 331 Level: intermediate 332 333 Notes: 334 The random type has to be set by PetscRandomSetType(). 335 336 This is only a primative "parallel" random number generator, it should NOT 337 be used for sophisticated parallel Monte Carlo methods since it will very likely 338 not have the correct statistics across processors. You can provide your own 339 parallel generator using PetscRandomRegister(); 340 341 If you create a PetscRandom() using PETSC_COMM_SELF on several processors then 342 the SAME random numbers will be generated on all those processors. Use PETSC_COMM_WORLD 343 or the appropriate parallel communicator to eliminate this issue. 344 345 Use VecSetRandom() to set the elements of a vector to random numbers. 346 347 Example of Usage: 348 .vb 349 PetscRandomCreate(PETSC_COMM_SELF,&r); 350 PetscRandomSetType(r,PETSCRAND48); 351 PetscRandomGetValue(r,&value1); 352 PetscRandomGetValueReal(r,&value2); 353 PetscRandomDestroy(&r); 354 .ve 355 356 Concepts: random numbers^creating 357 358 .seealso: PetscRandomSetType(), PetscRandomGetValue(), PetscRandomGetValueReal(), PetscRandomSetInterval(), 359 PetscRandomDestroy(), VecSetRandom(), PetscRandomType 360 @*/ 361 362 PetscErrorCode PetscRandomCreate(MPI_Comm comm,PetscRandom *r) 363 { 364 PetscRandom rr; 365 PetscErrorCode ierr; 366 PetscMPIInt rank; 367 368 PetscFunctionBegin; 369 PetscValidPointer(r,3); 370 *r = NULL; 371 #if !defined(PETSC_USE_DYNAMIC_LIBRARIES) 372 ierr = PetscRandomInitializePackage();CHKERRQ(ierr); 373 #endif 374 375 ierr = PetscHeaderCreate(rr,_p_PetscRandom,struct _PetscRandomOps,PETSC_RANDOM_CLASSID,"PetscRandom","Random number generator","Sys",comm,PetscRandomDestroy,0);CHKERRQ(ierr); 376 377 ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr); 378 379 rr->data = NULL; 380 rr->low = 0.0; 381 rr->width = 1.0; 382 rr->iset = PETSC_FALSE; 383 rr->seed = 0x12345678 + 76543*rank; 384 *r = rr; 385 PetscFunctionReturn(0); 386 } 387 388 #undef __FUNCT__ 389 #define __FUNCT__ "PetscRandomSeed" 390 /*@ 391 PetscRandomSeed - Seed the generator. 392 393 Not collective 394 395 Input Parameters: 396 . r - The random number generator context 397 398 Level: intermediate 399 400 Usage: 401 PetscRandomSetSeed(r,a positive integer); 402 PetscRandomSeed(r); PetscRandomGetValue() will now start with the new seed. 403 404 PetscRandomSeed(r) without a call to PetscRandomSetSeed() re-initializes 405 the seed. The random numbers generated will be the same as before. 406 407 Concepts: random numbers^seed 408 409 .seealso: PetscRandomCreate(), PetscRandomGetSeed(), PetscRandomSetSeed() 410 @*/ 411 PetscErrorCode PetscRandomSeed(PetscRandom r) 412 { 413 PetscErrorCode ierr; 414 415 PetscFunctionBegin; 416 PetscValidHeaderSpecific(r,PETSC_RANDOM_CLASSID,1); 417 PetscValidType(r,1); 418 419 ierr = (*r->ops->seed)(r);CHKERRQ(ierr); 420 ierr = PetscObjectStateIncrease((PetscObject)r);CHKERRQ(ierr); 421 PetscFunctionReturn(0); 422 } 423 424