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(NULL);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, "-random_view");CHKERRQ(ierr); 204 PetscFunctionReturn(0); 205 } 206 207 #undef __FUNCT__ 208 #define __FUNCT__ "PetscRandomView" 209 /*@C 210 PetscRandomView - Views a random number generator object. 211 212 Collective on PetscRandom 213 214 Input Parameters: 215 + rnd - The random number generator context 216 - viewer - an optional visualization context 217 218 Notes: 219 The available visualization contexts include 220 + PETSC_VIEWER_STDOUT_SELF - standard output (default) 221 - PETSC_VIEWER_STDOUT_WORLD - synchronized standard 222 output where only the first processor opens 223 the file. All other processors send their 224 data to the first processor to print. 225 226 You can change the format the vector is printed using the 227 option PetscViewerSetFormat(). 228 229 Level: beginner 230 231 .seealso: PetscRealView(), PetscScalarView(), PetscIntView() 232 @*/ 233 PetscErrorCode PetscRandomView(PetscRandom rnd,PetscViewer viewer) 234 { 235 PetscErrorCode ierr; 236 PetscBool iascii; 237 238 PetscFunctionBegin; 239 PetscValidHeaderSpecific(rnd,PETSC_RANDOM_CLASSID,1); 240 PetscValidType(rnd,1); 241 if (!viewer) { 242 ierr = PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)rnd),&viewer);CHKERRQ(ierr); 243 } 244 PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,2); 245 PetscCheckSameComm(rnd,1,viewer,2); 246 ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr); 247 if (iascii) { 248 PetscMPIInt rank; 249 ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)rnd),&rank);CHKERRQ(ierr); 250 ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_TRUE);CHKERRQ(ierr); 251 ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%D] Random type %s, seed %D\n",rank,((PetscObject)rnd)->type_name,rnd->seed);CHKERRQ(ierr); 252 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 253 ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_FALSE);CHKERRQ(ierr); 254 } else { 255 const char *tname; 256 ierr = PetscObjectGetName((PetscObject)viewer,&tname);CHKERRQ(ierr); 257 SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Viewer type %s not supported for this object",tname); 258 } 259 PetscFunctionReturn(0); 260 } 261 262 #undef __FUNCT__ 263 #define __FUNCT__ "PetscRandomViewFromOptions" 264 /*@ 265 PetscRandomViewFromOptions - This function visualizes the type and the seed of the generated random numbers based upon user options. 266 267 Collective on PetscRandom 268 269 Input Parameters: 270 . rnd - The random number generator context 271 . title - The title 272 273 Level: intermediate 274 275 .keywords: PetscRandom, view, options, database 276 .seealso: PetscRandomSetFromOptions() 277 @*/ 278 PetscErrorCode PetscRandomViewFromOptions(PetscRandom rnd, const char optionname[]) 279 { 280 PetscBool flg; 281 PetscViewer viewer; 282 PetscErrorCode ierr; 283 PetscViewerFormat format; 284 285 PetscFunctionBegin; 286 ierr = PetscOptionsGetViewer(PetscObjectComm((PetscObject)rnd),((PetscObject)rnd)->prefix,optionname,&viewer,&format,&flg);CHKERRQ(ierr); 287 if (flg) { 288 ierr = PetscViewerPushFormat(viewer,format);CHKERRQ(ierr); 289 ierr = PetscRandomView(rnd,viewer);CHKERRQ(ierr); 290 ierr = PetscViewerPopFormat(viewer);CHKERRQ(ierr); 291 ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr); 292 } 293 PetscFunctionReturn(0); 294 } 295 296 #if defined(PETSC_HAVE_AMS) 297 #undef __FUNCT__ 298 #define __FUNCT__ "PetscRandomPublish_Petsc" 299 static PetscErrorCode PetscRandomPublish_Petsc(PetscObject obj) 300 { 301 PetscRandom rand = (PetscRandom) obj; 302 PetscErrorCode ierr; 303 304 PetscFunctionBegin; 305 ierr = AMS_Memory_add_field(obj->amem,"Low",&rand->low,1,AMS_DOUBLE,AMS_READ,AMS_COMMON,AMS_REDUCT_UNDEF);CHKERRQ(ierr); 306 PetscFunctionReturn(0); 307 } 308 #endif 309 310 #undef __FUNCT__ 311 #define __FUNCT__ "PetscRandomCreate" 312 /*@ 313 PetscRandomCreate - Creates a context for generating random numbers, 314 and initializes the random-number generator. 315 316 Collective on MPI_Comm 317 318 Input Parameters: 319 + comm - MPI communicator 320 321 Output Parameter: 322 . r - the random number generator context 323 324 Level: intermediate 325 326 Notes: 327 The random type has to be set by PetscRandomSetType(). 328 329 This is only a primative "parallel" random number generator, it should NOT 330 be used for sophisticated parallel Monte Carlo methods since it will very likely 331 not have the correct statistics across processors. You can provide your own 332 parallel generator using PetscRandomRegister(); 333 334 If you create a PetscRandom() using PETSC_COMM_SELF on several processors then 335 the SAME random numbers will be generated on all those processors. Use PETSC_COMM_WORLD 336 or the appropriate parallel communicator to eliminate this issue. 337 338 Use VecSetRandom() to set the elements of a vector to random numbers. 339 340 Example of Usage: 341 .vb 342 PetscRandomCreate(PETSC_COMM_SELF,&r); 343 PetscRandomSetType(r,PETSCRAND48); 344 PetscRandomGetValue(r,&value1); 345 PetscRandomGetValueReal(r,&value2); 346 PetscRandomDestroy(&r); 347 .ve 348 349 Concepts: random numbers^creating 350 351 .seealso: PetscRandomSetType(), PetscRandomGetValue(), PetscRandomGetValueReal(), PetscRandomSetInterval(), 352 PetscRandomDestroy(), VecSetRandom(), PetscRandomType 353 @*/ 354 355 PetscErrorCode PetscRandomCreate(MPI_Comm comm,PetscRandom *r) 356 { 357 PetscRandom rr; 358 PetscErrorCode ierr; 359 PetscMPIInt rank; 360 361 PetscFunctionBegin; 362 PetscValidPointer(r,3); 363 *r = NULL; 364 #if !defined(PETSC_USE_DYNAMIC_LIBRARIES) 365 ierr = PetscRandomInitializePackage(NULL);CHKERRQ(ierr); 366 #endif 367 368 ierr = PetscHeaderCreate(rr,_p_PetscRandom,struct _PetscRandomOps,PETSC_RANDOM_CLASSID,"PetscRandom","Random number generator","Sys",comm,PetscRandomDestroy,0);CHKERRQ(ierr); 369 370 ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr); 371 372 rr->data = NULL; 373 rr->low = 0.0; 374 rr->width = 1.0; 375 rr->iset = PETSC_FALSE; 376 rr->seed = 0x12345678 + 76543*rank; 377 #if defined(PETSC_HAVE_AMS) 378 ((PetscObject)rr)->bops->publish = PetscRandomPublish_Petsc; 379 #endif 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