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(PetscOptions *PetscOptionsObject,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 ierr = PetscRandomRegisterAll();CHKERRQ(ierr); 149 ierr = PetscOptionsFList("-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(PetscOptionsObject,rnd);CHKERRQ(ierr); 192 193 /* Handle specific random generator's options */ 194 if (rnd->ops->setfromoptions) { 195 ierr = (*rnd->ops->setfromoptions)(PetscOptionsObject,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 issaws; 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,&issaws);CHKERRQ(ierr); 255 #endif 256 if (iascii) { 257 PetscMPIInt rank; 258 ierr = PetscObjectPrintClassNamePrefixType((PetscObject)rnd,viewer);CHKERRQ(ierr); 259 ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)rnd),&rank);CHKERRQ(ierr); 260 ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_TRUE);CHKERRQ(ierr); 261 ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%D] Random type %s, seed %D\n",rank,((PetscObject)rnd)->type_name,rnd->seed);CHKERRQ(ierr); 262 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 263 ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_FALSE);CHKERRQ(ierr); 264 #if defined(PETSC_HAVE_SAWS) 265 } else if (issaws) { 266 PetscMPIInt rank; 267 const char *name; 268 269 ierr = PetscObjectGetName((PetscObject)rnd,&name);CHKERRQ(ierr); 270 ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr); 271 if (!((PetscObject)rnd)->amsmem && !rank) { 272 char dir[1024]; 273 274 ierr = PetscObjectViewSAWs((PetscObject)rnd,viewer);CHKERRQ(ierr); 275 ierr = PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/Low",name);CHKERRQ(ierr); 276 PetscStackCallSAWs(SAWs_Register,(dir,&rnd->low,1,SAWs_READ,SAWs_DOUBLE)); 277 } 278 #endif 279 } 280 PetscFunctionReturn(0); 281 } 282 283 #undef __FUNCT__ 284 #define __FUNCT__ "PetscRandomCreate" 285 /*@ 286 PetscRandomCreate - Creates a context for generating random numbers, 287 and initializes the random-number generator. 288 289 Collective on MPI_Comm 290 291 Input Parameters: 292 + comm - MPI communicator 293 294 Output Parameter: 295 . r - the random number generator context 296 297 Level: intermediate 298 299 Notes: 300 The random type has to be set by PetscRandomSetType(). 301 302 This is only a primative "parallel" random number generator, it should NOT 303 be used for sophisticated parallel Monte Carlo methods since it will very likely 304 not have the correct statistics across processors. You can provide your own 305 parallel generator using PetscRandomRegister(); 306 307 If you create a PetscRandom() using PETSC_COMM_SELF on several processors then 308 the SAME random numbers will be generated on all those processors. Use PETSC_COMM_WORLD 309 or the appropriate parallel communicator to eliminate this issue. 310 311 Use VecSetRandom() to set the elements of a vector to random numbers. 312 313 Example of Usage: 314 .vb 315 PetscRandomCreate(PETSC_COMM_SELF,&r); 316 PetscRandomSetType(r,PETSCRAND48); 317 PetscRandomGetValue(r,&value1); 318 PetscRandomGetValueReal(r,&value2); 319 PetscRandomDestroy(&r); 320 .ve 321 322 Concepts: random numbers^creating 323 324 .seealso: PetscRandomSetType(), PetscRandomGetValue(), PetscRandomGetValueReal(), PetscRandomSetInterval(), 325 PetscRandomDestroy(), VecSetRandom(), PetscRandomType 326 @*/ 327 328 PetscErrorCode PetscRandomCreate(MPI_Comm comm,PetscRandom *r) 329 { 330 PetscRandom rr; 331 PetscErrorCode ierr; 332 PetscMPIInt rank; 333 334 PetscFunctionBegin; 335 PetscValidPointer(r,3); 336 *r = NULL; 337 ierr = PetscRandomInitializePackage();CHKERRQ(ierr); 338 339 ierr = PetscHeaderCreate(rr,_p_PetscRandom,struct _PetscRandomOps,PETSC_RANDOM_CLASSID,"PetscRandom","Random number generator","Sys",comm,PetscRandomDestroy,0);CHKERRQ(ierr); 340 341 ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr); 342 343 rr->data = NULL; 344 rr->low = 0.0; 345 rr->width = 1.0; 346 rr->iset = PETSC_FALSE; 347 rr->seed = 0x12345678 + 76543*rank; 348 *r = rr; 349 PetscFunctionReturn(0); 350 } 351 352 #undef __FUNCT__ 353 #define __FUNCT__ "PetscRandomSeed" 354 /*@ 355 PetscRandomSeed - Seed the generator. 356 357 Not collective 358 359 Input Parameters: 360 . r - The random number generator context 361 362 Level: intermediate 363 364 Usage: 365 PetscRandomSetSeed(r,a positive integer); 366 PetscRandomSeed(r); PetscRandomGetValue() will now start with the new seed. 367 368 PetscRandomSeed(r) without a call to PetscRandomSetSeed() re-initializes 369 the seed. The random numbers generated will be the same as before. 370 371 Concepts: random numbers^seed 372 373 .seealso: PetscRandomCreate(), PetscRandomGetSeed(), PetscRandomSetSeed() 374 @*/ 375 PetscErrorCode PetscRandomSeed(PetscRandom r) 376 { 377 PetscErrorCode ierr; 378 379 PetscFunctionBegin; 380 PetscValidHeaderSpecific(r,PETSC_RANDOM_CLASSID,1); 381 PetscValidType(r,1); 382 383 ierr = (*r->ops->seed)(r);CHKERRQ(ierr); 384 ierr = PetscObjectStateIncrease((PetscObject)r);CHKERRQ(ierr); 385 PetscFunctionReturn(0); 386 } 387 388