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_AMS) 208 #include <petscviewerams.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_AMS) 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_AMS) 254 ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERAMS,&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_AMS) 264 } else if (isams) { 265 if (((PetscObject)rnd)->amsmem == -1) { 266 ierr = PetscObjectViewAMS((PetscObject)rnd,viewer);CHKERRQ(ierr); 267 PetscStackCallAMS(AMS_Memory_add_field,(((PetscObject)rnd)->amsmem,"Low",&rnd->low,1,AMS_DOUBLE,AMS_READ,AMS_COMMON,AMS_REDUCT_UNDEF)); 268 } 269 #endif 270 } 271 PetscFunctionReturn(0); 272 } 273 274 #undef __FUNCT__ 275 #define __FUNCT__ "PetscRandomViewFromOptions" 276 /* 277 PetscRandomViewFromOptions - This function visualizes the type and the seed of the generated random numbers based upon user options. 278 279 Collective on PetscRandom 280 281 Input Parameters: 282 + rnd - The random number generator context 283 . prefix - prefix to use for viewing, or NULL to use prefix of 'rnd' 284 - optionname - option to activate viewing 285 286 Level: intermediate 287 288 .keywords: PetscRandom, view, options, database 289 .seealso: PetscRandomSetFromOptions() 290 */ 291 PetscErrorCode PetscRandomViewFromOptions(PetscRandom rnd, const char prefix[], const char optionname[]) 292 { 293 PetscBool flg; 294 PetscViewer viewer; 295 PetscErrorCode ierr; 296 PetscViewerFormat format; 297 298 PetscFunctionBegin; 299 if (prefix) { 300 ierr = PetscOptionsGetViewer(PetscObjectComm((PetscObject)rnd),prefix,optionname,&viewer,&format,&flg);CHKERRQ(ierr); 301 } else { 302 ierr = PetscOptionsGetViewer(PetscObjectComm((PetscObject)rnd),((PetscObject)rnd)->prefix,optionname,&viewer,&format,&flg);CHKERRQ(ierr); 303 } 304 if (flg) { 305 ierr = PetscViewerPushFormat(viewer,format);CHKERRQ(ierr); 306 ierr = PetscRandomView(rnd,viewer);CHKERRQ(ierr); 307 ierr = PetscViewerPopFormat(viewer);CHKERRQ(ierr); 308 ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr); 309 } 310 PetscFunctionReturn(0); 311 } 312 313 #undef __FUNCT__ 314 #define __FUNCT__ "PetscRandomCreate" 315 /*@ 316 PetscRandomCreate - Creates a context for generating random numbers, 317 and initializes the random-number generator. 318 319 Collective on MPI_Comm 320 321 Input Parameters: 322 + comm - MPI communicator 323 324 Output Parameter: 325 . r - the random number generator context 326 327 Level: intermediate 328 329 Notes: 330 The random type has to be set by PetscRandomSetType(). 331 332 This is only a primative "parallel" random number generator, it should NOT 333 be used for sophisticated parallel Monte Carlo methods since it will very likely 334 not have the correct statistics across processors. You can provide your own 335 parallel generator using PetscRandomRegister(); 336 337 If you create a PetscRandom() using PETSC_COMM_SELF on several processors then 338 the SAME random numbers will be generated on all those processors. Use PETSC_COMM_WORLD 339 or the appropriate parallel communicator to eliminate this issue. 340 341 Use VecSetRandom() to set the elements of a vector to random numbers. 342 343 Example of Usage: 344 .vb 345 PetscRandomCreate(PETSC_COMM_SELF,&r); 346 PetscRandomSetType(r,PETSCRAND48); 347 PetscRandomGetValue(r,&value1); 348 PetscRandomGetValueReal(r,&value2); 349 PetscRandomDestroy(&r); 350 .ve 351 352 Concepts: random numbers^creating 353 354 .seealso: PetscRandomSetType(), PetscRandomGetValue(), PetscRandomGetValueReal(), PetscRandomSetInterval(), 355 PetscRandomDestroy(), VecSetRandom(), PetscRandomType 356 @*/ 357 358 PetscErrorCode PetscRandomCreate(MPI_Comm comm,PetscRandom *r) 359 { 360 PetscRandom rr; 361 PetscErrorCode ierr; 362 PetscMPIInt rank; 363 364 PetscFunctionBegin; 365 PetscValidPointer(r,3); 366 *r = NULL; 367 #if !defined(PETSC_USE_DYNAMIC_LIBRARIES) 368 ierr = PetscRandomInitializePackage();CHKERRQ(ierr); 369 #endif 370 371 ierr = PetscHeaderCreate(rr,_p_PetscRandom,struct _PetscRandomOps,PETSC_RANDOM_CLASSID,"PetscRandom","Random number generator","Sys",comm,PetscRandomDestroy,0);CHKERRQ(ierr); 372 373 ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr); 374 375 rr->data = NULL; 376 rr->low = 0.0; 377 rr->width = 1.0; 378 rr->iset = PETSC_FALSE; 379 rr->seed = 0x12345678 + 76543*rank; 380 *r = rr; 381 PetscFunctionReturn(0); 382 } 383 384 #undef __FUNCT__ 385 #define __FUNCT__ "PetscRandomSeed" 386 /*@ 387 PetscRandomSeed - Seed the generator. 388 389 Not collective 390 391 Input Parameters: 392 . r - The random number generator context 393 394 Level: intermediate 395 396 Usage: 397 PetscRandomSetSeed(r,a positive integer); 398 PetscRandomSeed(r); PetscRandomGetValue() will now start with the new seed. 399 400 PetscRandomSeed(r) without a call to PetscRandomSetSeed() re-initializes 401 the seed. The random numbers generated will be the same as before. 402 403 Concepts: random numbers^seed 404 405 .seealso: PetscRandomCreate(), PetscRandomGetSeed(), PetscRandomSetSeed() 406 @*/ 407 PetscErrorCode PetscRandomSeed(PetscRandom r) 408 { 409 PetscErrorCode ierr; 410 411 PetscFunctionBegin; 412 PetscValidHeaderSpecific(r,PETSC_RANDOM_CLASSID,1); 413 PetscValidType(r,1); 414 415 ierr = (*r->ops->seed)(r);CHKERRQ(ierr); 416 ierr = PetscObjectStateIncrease((PetscObject)r);CHKERRQ(ierr); 417 PetscFunctionReturn(0); 418 } 419 420