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