1 2 #include <../src/snes/impls/vi/viimpl.h> /*I "petscsnes.h" I*/ 3 #include <../include/private/kspimpl.h> 4 #include <../include/private/matimpl.h> 5 6 #undef __FUNCT__ 7 #define __FUNCT__ "SNESMonitorVI" 8 PetscErrorCode SNESMonitorVI(SNES snes,PetscInt its,PetscReal fgnorm,void *dummy) 9 { 10 PetscErrorCode ierr; 11 SNES_VI *vi = (SNES_VI*)snes->data; 12 PetscViewerASCIIMonitor viewer = (PetscViewerASCIIMonitor) dummy; 13 const PetscScalar *x,*xl,*xu,*f; 14 PetscInt i,n,act = 0; 15 PetscReal rnorm,fnorm; 16 17 PetscFunctionBegin; 18 if (!dummy) { 19 ierr = PetscViewerASCIIMonitorCreate(((PetscObject)snes)->comm,"stdout",0,&viewer);CHKERRQ(ierr); 20 } 21 ierr = VecGetLocalSize(snes->vec_sol,&n);CHKERRQ(ierr); 22 ierr = VecGetArrayRead(vi->xl,&xl);CHKERRQ(ierr); 23 ierr = VecGetArrayRead(vi->xu,&xu);CHKERRQ(ierr); 24 ierr = VecGetArrayRead(snes->vec_sol,&x);CHKERRQ(ierr); 25 ierr = VecGetArrayRead(snes->vec_func,&f);CHKERRQ(ierr); 26 27 rnorm = 0.0; 28 for (i=0; i<n; i++) { 29 if (((x[i] > xl[i] + 1.e-8 || (f[i] < 0.0)) && ((x[i] < xu[i] - 1.e-8) || f[i] > 0.0))) rnorm += f[i]*f[i]; 30 else act++; 31 } 32 ierr = VecRestoreArrayRead(snes->vec_func,&f);CHKERRQ(ierr); 33 ierr = VecRestoreArrayRead(vi->xl,&xl);CHKERRQ(ierr); 34 ierr = VecRestoreArrayRead(vi->xu,&xu);CHKERRQ(ierr); 35 ierr = VecRestoreArrayRead(snes->vec_sol,&x);CHKERRQ(ierr); 36 ierr = MPI_Allreduce(&rnorm,&fnorm,1,MPIU_REAL,MPIU_SUM,((PetscObject)snes)->comm);CHKERRQ(ierr); 37 fnorm = sqrt(fnorm); 38 ierr = PetscViewerASCIIMonitorPrintf(viewer,"%3D SNES VI Function norm %14.12e Active constraints %D\n",its,fnorm,act);CHKERRQ(ierr); 39 if (!dummy) { 40 ierr = PetscViewerASCIIMonitorDestroy(viewer);CHKERRQ(ierr); 41 } 42 PetscFunctionReturn(0); 43 } 44 45 /* 46 Checks if J^T F = 0 which implies we've found a local minimum of the norm of the function, 47 || F(u) ||_2 but not a zero, F(u) = 0. In the case when one cannot compute J^T F we use the fact that 48 0 = (J^T F)^T W = F^T J W iff W not in the null space of J. Thanks for Jorge More 49 for this trick. One assumes that the probability that W is in the null space of J is very, very small. 50 */ 51 #undef __FUNCT__ 52 #define __FUNCT__ "SNESVICheckLocalMin_Private" 53 PetscErrorCode SNESVICheckLocalMin_Private(SNES snes,Mat A,Vec F,Vec W,PetscReal fnorm,PetscBool *ismin) 54 { 55 PetscReal a1; 56 PetscErrorCode ierr; 57 PetscBool hastranspose; 58 59 PetscFunctionBegin; 60 *ismin = PETSC_FALSE; 61 ierr = MatHasOperation(A,MATOP_MULT_TRANSPOSE,&hastranspose);CHKERRQ(ierr); 62 if (hastranspose) { 63 /* Compute || J^T F|| */ 64 ierr = MatMultTranspose(A,F,W);CHKERRQ(ierr); 65 ierr = VecNorm(W,NORM_2,&a1);CHKERRQ(ierr); 66 ierr = PetscInfo1(snes,"|| J^T F|| %G near zero implies found a local minimum\n",a1/fnorm);CHKERRQ(ierr); 67 if (a1/fnorm < 1.e-4) *ismin = PETSC_TRUE; 68 } else { 69 Vec work; 70 PetscScalar result; 71 PetscReal wnorm; 72 73 ierr = VecSetRandom(W,PETSC_NULL);CHKERRQ(ierr); 74 ierr = VecNorm(W,NORM_2,&wnorm);CHKERRQ(ierr); 75 ierr = VecDuplicate(W,&work);CHKERRQ(ierr); 76 ierr = MatMult(A,W,work);CHKERRQ(ierr); 77 ierr = VecDot(F,work,&result);CHKERRQ(ierr); 78 ierr = VecDestroy(work);CHKERRQ(ierr); 79 a1 = PetscAbsScalar(result)/(fnorm*wnorm); 80 ierr = PetscInfo1(snes,"(F^T J random)/(|| F ||*||random|| %G near zero implies found a local minimum\n",a1);CHKERRQ(ierr); 81 if (a1 < 1.e-4) *ismin = PETSC_TRUE; 82 } 83 PetscFunctionReturn(0); 84 } 85 86 /* 87 Checks if J^T(F - J*X) = 0 88 */ 89 #undef __FUNCT__ 90 #define __FUNCT__ "SNESVICheckResidual_Private" 91 PetscErrorCode SNESVICheckResidual_Private(SNES snes,Mat A,Vec F,Vec X,Vec W1,Vec W2) 92 { 93 PetscReal a1,a2; 94 PetscErrorCode ierr; 95 PetscBool hastranspose; 96 97 PetscFunctionBegin; 98 ierr = MatHasOperation(A,MATOP_MULT_TRANSPOSE,&hastranspose);CHKERRQ(ierr); 99 if (hastranspose) { 100 ierr = MatMult(A,X,W1);CHKERRQ(ierr); 101 ierr = VecAXPY(W1,-1.0,F);CHKERRQ(ierr); 102 103 /* Compute || J^T W|| */ 104 ierr = MatMultTranspose(A,W1,W2);CHKERRQ(ierr); 105 ierr = VecNorm(W1,NORM_2,&a1);CHKERRQ(ierr); 106 ierr = VecNorm(W2,NORM_2,&a2);CHKERRQ(ierr); 107 if (a1 != 0.0) { 108 ierr = PetscInfo1(snes,"||J^T(F-Ax)||/||F-AX|| %G near zero implies inconsistent rhs\n",a2/a1);CHKERRQ(ierr); 109 } 110 } 111 PetscFunctionReturn(0); 112 } 113 114 /* 115 SNESDefaultConverged_VI - Checks the convergence of the semismooth newton algorithm. 116 117 Notes: 118 The convergence criterion currently implemented is 119 merit < abstol 120 merit < rtol*merit_initial 121 */ 122 #undef __FUNCT__ 123 #define __FUNCT__ "SNESDefaultConverged_VI" 124 PetscErrorCode SNESDefaultConverged_VI(SNES snes,PetscInt it,PetscReal xnorm,PetscReal gradnorm,PetscReal fnorm,SNESConvergedReason *reason,void *dummy) 125 { 126 PetscErrorCode ierr; 127 128 PetscFunctionBegin; 129 PetscValidHeaderSpecific(snes,SNES_CLASSID,1); 130 PetscValidPointer(reason,6); 131 132 *reason = SNES_CONVERGED_ITERATING; 133 134 if (!it) { 135 /* set parameter for default relative tolerance convergence test */ 136 snes->ttol = fnorm*snes->rtol; 137 } 138 if (fnorm != fnorm) { 139 ierr = PetscInfo(snes,"Failed to converged, function norm is NaN\n");CHKERRQ(ierr); 140 *reason = SNES_DIVERGED_FNORM_NAN; 141 } else if (fnorm < snes->abstol) { 142 ierr = PetscInfo2(snes,"Converged due to function norm %G < %G\n",fnorm,snes->abstol);CHKERRQ(ierr); 143 *reason = SNES_CONVERGED_FNORM_ABS; 144 } else if (snes->nfuncs >= snes->max_funcs) { 145 ierr = PetscInfo2(snes,"Exceeded maximum number of function evaluations: %D > %D\n",snes->nfuncs,snes->max_funcs);CHKERRQ(ierr); 146 *reason = SNES_DIVERGED_FUNCTION_COUNT; 147 } 148 149 if (it && !*reason) { 150 if (fnorm < snes->ttol) { 151 ierr = PetscInfo2(snes,"Converged due to function norm %G < %G (relative tolerance)\n",fnorm,snes->ttol);CHKERRQ(ierr); 152 *reason = SNES_CONVERGED_FNORM_RELATIVE; 153 } 154 } 155 PetscFunctionReturn(0); 156 } 157 158 /* 159 SNESVIComputeMeritFunction - Evaluates the merit function for the mixed complementarity problem. 160 161 Input Parameter: 162 . phi - the semismooth function 163 164 Output Parameter: 165 . merit - the merit function 166 . phinorm - ||phi|| 167 168 Notes: 169 The merit function for the mixed complementarity problem is defined as 170 merit = 0.5*phi^T*phi 171 */ 172 #undef __FUNCT__ 173 #define __FUNCT__ "SNESVIComputeMeritFunction" 174 static PetscErrorCode SNESVIComputeMeritFunction(Vec phi, PetscReal* merit,PetscReal* phinorm) 175 { 176 PetscErrorCode ierr; 177 178 PetscFunctionBegin; 179 ierr = VecNormBegin(phi,NORM_2,phinorm);CHKERRQ(ierr); 180 ierr = VecNormEnd(phi,NORM_2,phinorm);CHKERRQ(ierr); 181 182 *merit = 0.5*(*phinorm)*(*phinorm); 183 PetscFunctionReturn(0); 184 } 185 186 PETSC_STATIC_INLINE PetscScalar Phi(PetscScalar a,PetscScalar b) 187 { 188 return a + b - sqrt(a*a + b*b); 189 } 190 191 PETSC_STATIC_INLINE PetscScalar DPhi(PetscScalar a,PetscScalar b) 192 { 193 if ((PetscAbsScalar(a) >= 1.e-6) || (PetscAbsScalar(b) >= 1.e-6)) return 1.0 - a/ sqrt(a*a + b*b); 194 else return .5; 195 } 196 197 /* 198 SNESVIComputeFunction - Reformulates a system of nonlinear equations in mixed complementarity form to a system of nonlinear equations in semismooth form. 199 200 Input Parameters: 201 . snes - the SNES context 202 . x - current iterate 203 . functx - user defined function context 204 205 Output Parameters: 206 . phi - Semismooth function 207 208 */ 209 #undef __FUNCT__ 210 #define __FUNCT__ "SNESVIComputeFunction" 211 static PetscErrorCode SNESVIComputeFunction(SNES snes,Vec X,Vec phi,void* functx) 212 { 213 PetscErrorCode ierr; 214 SNES_VI *vi = (SNES_VI*)snes->data; 215 Vec Xl = vi->xl,Xu = vi->xu,F = snes->vec_func; 216 PetscScalar *phi_arr,*x_arr,*f_arr,*l,*u; 217 PetscInt i,nlocal; 218 219 PetscFunctionBegin; 220 ierr = (*vi->computeuserfunction)(snes,X,F,functx);CHKERRQ(ierr); 221 ierr = VecGetLocalSize(X,&nlocal);CHKERRQ(ierr); 222 ierr = VecGetArray(X,&x_arr);CHKERRQ(ierr); 223 ierr = VecGetArray(F,&f_arr);CHKERRQ(ierr); 224 ierr = VecGetArray(Xl,&l);CHKERRQ(ierr); 225 ierr = VecGetArray(Xu,&u);CHKERRQ(ierr); 226 ierr = VecGetArray(phi,&phi_arr);CHKERRQ(ierr); 227 228 for (i=0;i < nlocal;i++) { 229 if ((l[i] <= PETSC_VI_NINF) && (u[i] >= PETSC_VI_INF)) { /* no constraints on variable */ 230 phi_arr[i] = f_arr[i]; 231 } else if (l[i] <= PETSC_VI_NINF) { /* upper bound on variable only */ 232 phi_arr[i] = -Phi(u[i] - x_arr[i],-f_arr[i]); 233 } else if (u[i] >= PETSC_VI_INF) { /* lower bound on variable only */ 234 phi_arr[i] = Phi(x_arr[i] - l[i],f_arr[i]); 235 } else if (l[i] == u[i]) { 236 phi_arr[i] = l[i] - x_arr[i]; 237 } else { /* both bounds on variable */ 238 phi_arr[i] = Phi(x_arr[i] - l[i],-Phi(u[i] - x_arr[i],-f_arr[i])); 239 } 240 } 241 242 ierr = VecRestoreArray(X,&x_arr);CHKERRQ(ierr); 243 ierr = VecRestoreArray(F,&f_arr);CHKERRQ(ierr); 244 ierr = VecRestoreArray(Xl,&l);CHKERRQ(ierr); 245 ierr = VecRestoreArray(Xu,&u);CHKERRQ(ierr); 246 ierr = VecRestoreArray(phi,&phi_arr);CHKERRQ(ierr); 247 PetscFunctionReturn(0); 248 } 249 250 /* 251 SNESVIComputeBsubdifferentialVectors - Computes the diagonal shift (Da) and row scaling (Db) vectors needed for the 252 the semismooth jacobian. 253 */ 254 #undef __FUNCT__ 255 #define __FUNCT__ "SNESVIComputeBsubdifferentialVectors" 256 PetscErrorCode SNESVIComputeBsubdifferentialVectors(SNES snes,Vec X,Vec F,Mat jac,Vec Da,Vec Db) 257 { 258 PetscErrorCode ierr; 259 SNES_VI *vi = (SNES_VI*)snes->data; 260 PetscScalar *l,*u,*x,*f,*da,*db,da1,da2,db1,db2; 261 PetscInt i,nlocal; 262 263 PetscFunctionBegin; 264 265 ierr = VecGetArray(X,&x);CHKERRQ(ierr); 266 ierr = VecGetArray(F,&f);CHKERRQ(ierr); 267 ierr = VecGetArray(vi->xl,&l);CHKERRQ(ierr); 268 ierr = VecGetArray(vi->xu,&u);CHKERRQ(ierr); 269 ierr = VecGetArray(Da,&da);CHKERRQ(ierr); 270 ierr = VecGetArray(Db,&db);CHKERRQ(ierr); 271 ierr = VecGetLocalSize(X,&nlocal);CHKERRQ(ierr); 272 273 for (i=0;i< nlocal;i++) { 274 if ((l[i] <= PETSC_VI_NINF) && (u[i] >= PETSC_VI_INF)) {/* no constraints on variable */ 275 da[i] = 0; 276 db[i] = 1; 277 } else if (l[i] <= PETSC_VI_NINF) { /* upper bound on variable only */ 278 da[i] = DPhi(u[i] - x[i], -f[i]); 279 db[i] = DPhi(-f[i],u[i] - x[i]); 280 } else if (u[i] >= PETSC_VI_INF) { /* lower bound on variable only */ 281 da[i] = DPhi(x[i] - l[i], f[i]); 282 db[i] = DPhi(f[i],x[i] - l[i]); 283 } else if (l[i] == u[i]) { /* fixed variable */ 284 da[i] = 1; 285 db[i] = 0; 286 } else { /* upper and lower bounds on variable */ 287 da1 = DPhi(x[i] - l[i], -Phi(u[i] - x[i], -f[i])); 288 db1 = DPhi(-Phi(u[i] - x[i], -f[i]),x[i] - l[i]); 289 da2 = DPhi(u[i] - x[i], -f[i]); 290 db2 = DPhi(-f[i],u[i] - x[i]); 291 da[i] = da1 + db1*da2; 292 db[i] = db1*db2; 293 } 294 } 295 296 ierr = VecRestoreArray(X,&x);CHKERRQ(ierr); 297 ierr = VecRestoreArray(F,&f);CHKERRQ(ierr); 298 ierr = VecRestoreArray(vi->xl,&l);CHKERRQ(ierr); 299 ierr = VecRestoreArray(vi->xu,&u);CHKERRQ(ierr); 300 ierr = VecRestoreArray(Da,&da);CHKERRQ(ierr); 301 ierr = VecRestoreArray(Db,&db);CHKERRQ(ierr); 302 PetscFunctionReturn(0); 303 } 304 305 /* 306 SNESVIComputeJacobian - Computes the jacobian of the semismooth function.The Jacobian for the semismooth function is an element of the B-subdifferential of the Fischer-Burmeister function for complementarity problems. 307 308 Input Parameters: 309 . Da - Diagonal shift vector for the semismooth jacobian. 310 . Db - Row scaling vector for the semismooth jacobian. 311 312 Output Parameters: 313 . jac - semismooth jacobian 314 . jac_pre - optional preconditioning matrix 315 316 Notes: 317 The semismooth jacobian matrix is given by 318 jac = Da + Db*jacfun 319 where Db is the row scaling matrix stored as a vector, 320 Da is the diagonal perturbation matrix stored as a vector 321 and jacfun is the jacobian of the original nonlinear function. 322 */ 323 #undef __FUNCT__ 324 #define __FUNCT__ "SNESVIComputeJacobian" 325 PetscErrorCode SNESVIComputeJacobian(Mat jac, Mat jac_pre,Vec Da, Vec Db) 326 { 327 PetscErrorCode ierr; 328 329 /* Do row scaling and add diagonal perturbation */ 330 ierr = MatDiagonalScale(jac,Db,PETSC_NULL);CHKERRQ(ierr); 331 ierr = MatDiagonalSet(jac,Da,ADD_VALUES);CHKERRQ(ierr); 332 if (jac != jac_pre) { /* If jac and jac_pre are different */ 333 ierr = MatDiagonalScale(jac_pre,Db,PETSC_NULL); 334 ierr = MatDiagonalSet(jac_pre,Da,ADD_VALUES);CHKERRQ(ierr); 335 } 336 PetscFunctionReturn(0); 337 } 338 339 /* 340 SNESVIComputeMeritFunctionGradient - Computes the gradient of the merit function psi. 341 342 Input Parameters: 343 phi - semismooth function. 344 H - semismooth jacobian 345 346 Output Parameters: 347 dpsi - merit function gradient 348 349 Notes: 350 The merit function gradient is computed as follows 351 dpsi = H^T*phi 352 */ 353 #undef __FUNCT__ 354 #define __FUNCT__ "SNESVIComputeMeritFunctionGradient" 355 PetscErrorCode SNESVIComputeMeritFunctionGradient(Mat H, Vec phi, Vec dpsi) 356 { 357 PetscErrorCode ierr; 358 359 PetscFunctionBegin; 360 ierr = MatMultTranspose(H,phi,dpsi);CHKERRQ(ierr); 361 PetscFunctionReturn(0); 362 } 363 364 /* -------------------------------------------------------------------------- */ 365 /* 366 SNESVIProjectOntoBounds - Projects X onto the feasible region so that Xl[i] <= X[i] <= Xu[i] for i = 1...n. 367 368 Input Parameters: 369 . SNES - nonlinear solver context 370 371 Output Parameters: 372 . X - Bound projected X 373 374 */ 375 376 #undef __FUNCT__ 377 #define __FUNCT__ "SNESVIProjectOntoBounds" 378 PetscErrorCode SNESVIProjectOntoBounds(SNES snes,Vec X) 379 { 380 PetscErrorCode ierr; 381 SNES_VI *vi = (SNES_VI*)snes->data; 382 const PetscScalar *xl,*xu; 383 PetscScalar *x; 384 PetscInt i,n; 385 386 PetscFunctionBegin; 387 ierr = VecGetLocalSize(X,&n);CHKERRQ(ierr); 388 ierr = VecGetArray(X,&x);CHKERRQ(ierr); 389 ierr = VecGetArrayRead(vi->xl,&xl);CHKERRQ(ierr); 390 ierr = VecGetArrayRead(vi->xu,&xu);CHKERRQ(ierr); 391 392 for(i = 0;i<n;i++) { 393 if (x[i] < xl[i]) x[i] = xl[i]; 394 else if (x[i] > xu[i]) x[i] = xu[i]; 395 } 396 ierr = VecRestoreArray(X,&x);CHKERRQ(ierr); 397 ierr = VecRestoreArrayRead(vi->xl,&xl);CHKERRQ(ierr); 398 ierr = VecRestoreArrayRead(vi->xu,&xu);CHKERRQ(ierr); 399 PetscFunctionReturn(0); 400 } 401 402 /* -------------------------------------------------------------------- 403 404 This file implements a semismooth truncated Newton method with a line search, 405 for solving a system of nonlinear equations in complementarity form, using the KSP, Vec, 406 and Mat interfaces for linear solvers, vectors, and matrices, 407 respectively. 408 409 The following basic routines are required for each nonlinear solver: 410 SNESCreate_XXX() - Creates a nonlinear solver context 411 SNESSetFromOptions_XXX() - Sets runtime options 412 SNESSolve_XXX() - Solves the nonlinear system 413 SNESDestroy_XXX() - Destroys the nonlinear solver context 414 The suffix "_XXX" denotes a particular implementation, in this case 415 we use _VI (e.g., SNESCreate_VI, SNESSolve_VI) for solving 416 systems of nonlinear equations with a line search (LS) method. 417 These routines are actually called via the common user interface 418 routines SNESCreate(), SNESSetFromOptions(), SNESSolve(), and 419 SNESDestroy(), so the application code interface remains identical 420 for all nonlinear solvers. 421 422 Another key routine is: 423 SNESSetUp_XXX() - Prepares for the use of a nonlinear solver 424 by setting data structures and options. The interface routine SNESSetUp() 425 is not usually called directly by the user, but instead is called by 426 SNESSolve() if necessary. 427 428 Additional basic routines are: 429 SNESView_XXX() - Prints details of runtime options that 430 have actually been used. 431 These are called by application codes via the interface routines 432 SNESView(). 433 434 The various types of solvers (preconditioners, Krylov subspace methods, 435 nonlinear solvers, timesteppers) are all organized similarly, so the 436 above description applies to these categories also. 437 438 -------------------------------------------------------------------- */ 439 /* 440 SNESSolveVI_SS - Solves the complementarity problem with a semismooth Newton 441 method using a line search. 442 443 Input Parameters: 444 . snes - the SNES context 445 446 Output Parameter: 447 . outits - number of iterations until termination 448 449 Application Interface Routine: SNESSolve() 450 451 Notes: 452 This implements essentially a semismooth Newton method with a 453 line search. The default line search does not do any line seach 454 but rather takes a full newton step. 455 */ 456 #undef __FUNCT__ 457 #define __FUNCT__ "SNESSolveVI_SS" 458 PetscErrorCode SNESSolveVI_SS(SNES snes) 459 { 460 SNES_VI *vi = (SNES_VI*)snes->data; 461 PetscErrorCode ierr; 462 PetscInt maxits,i,lits; 463 PetscBool lssucceed; 464 MatStructure flg = DIFFERENT_NONZERO_PATTERN; 465 PetscReal gnorm,xnorm=0,ynorm; 466 Vec Y,X,F,G,W; 467 KSPConvergedReason kspreason; 468 469 PetscFunctionBegin; 470 vi->computeuserfunction = snes->ops->computefunction; 471 snes->ops->computefunction = SNESVIComputeFunction; 472 473 snes->numFailures = 0; 474 snes->numLinearSolveFailures = 0; 475 snes->reason = SNES_CONVERGED_ITERATING; 476 477 maxits = snes->max_its; /* maximum number of iterations */ 478 X = snes->vec_sol; /* solution vector */ 479 F = snes->vec_func; /* residual vector */ 480 Y = snes->work[0]; /* work vectors */ 481 G = snes->work[1]; 482 W = snes->work[2]; 483 484 ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); 485 snes->iter = 0; 486 snes->norm = 0.0; 487 ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); 488 489 ierr = SNESVIProjectOntoBounds(snes,X);CHKERRQ(ierr); 490 ierr = SNESComputeFunction(snes,X,vi->phi);CHKERRQ(ierr); 491 if (snes->domainerror) { 492 snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; 493 snes->ops->computefunction = vi->computeuserfunction; 494 PetscFunctionReturn(0); 495 } 496 /* Compute Merit function */ 497 ierr = SNESVIComputeMeritFunction(vi->phi,&vi->merit,&vi->phinorm);CHKERRQ(ierr); 498 499 ierr = VecNormBegin(X,NORM_2,&xnorm);CHKERRQ(ierr); /* xnorm <- ||x|| */ 500 ierr = VecNormEnd(X,NORM_2,&xnorm);CHKERRQ(ierr); 501 if (PetscIsInfOrNanReal(vi->merit)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 502 503 ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); 504 snes->norm = vi->phinorm; 505 ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); 506 SNESLogConvHistory(snes,vi->phinorm,0); 507 SNESMonitor(snes,0,vi->phinorm); 508 509 /* set parameter for default relative tolerance convergence test */ 510 snes->ttol = vi->phinorm*snes->rtol; 511 /* test convergence */ 512 ierr = (*snes->ops->converged)(snes,0,0.0,0.0,vi->phinorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); 513 if (snes->reason) { 514 snes->ops->computefunction = vi->computeuserfunction; 515 PetscFunctionReturn(0); 516 } 517 518 for (i=0; i<maxits; i++) { 519 520 /* Call general purpose update function */ 521 if (snes->ops->update) { 522 ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr); 523 } 524 525 /* Solve J Y = Phi, where J is the semismooth jacobian */ 526 /* Get the nonlinear function jacobian */ 527 ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr); 528 /* Get the diagonal shift and row scaling vectors */ 529 ierr = SNESVIComputeBsubdifferentialVectors(snes,X,F,snes->jacobian,vi->Da,vi->Db);CHKERRQ(ierr); 530 /* Compute the semismooth jacobian */ 531 ierr = SNESVIComputeJacobian(snes->jacobian,snes->jacobian_pre,vi->Da,vi->Db);CHKERRQ(ierr); 532 /* Compute the merit function gradient */ 533 ierr = SNESVIComputeMeritFunctionGradient(snes->jacobian,vi->phi,vi->dpsi);CHKERRQ(ierr); 534 ierr = KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre,flg);CHKERRQ(ierr); 535 ierr = SNES_KSPSolve(snes,snes->ksp,vi->phi,Y);CHKERRQ(ierr); 536 ierr = KSPGetConvergedReason(snes->ksp,&kspreason);CHKERRQ(ierr); 537 538 if (kspreason < 0) { 539 if (++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) { 540 ierr = PetscInfo2(snes,"iter=%D, number linear solve failures %D greater than current SNES allowed, stopping solve\n",snes->iter,snes->numLinearSolveFailures);CHKERRQ(ierr); 541 snes->reason = SNES_DIVERGED_LINEAR_SOLVE; 542 break; 543 } 544 } 545 ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr); 546 snes->linear_its += lits; 547 ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr); 548 /* 549 if (vi->precheckstep) { 550 PetscBool changed_y = PETSC_FALSE; 551 ierr = (*vi->precheckstep)(snes,X,Y,vi->precheck,&changed_y);CHKERRQ(ierr); 552 } 553 554 if (PetscLogPrintInfo){ 555 ierr = SNESVICheckResidual_Private(snes,snes->jacobian,F,Y,G,W);CHKERRQ(ierr); 556 } 557 */ 558 /* Compute a (scaled) negative update in the line search routine: 559 Y <- X - lambda*Y 560 and evaluate G = function(Y) (depends on the line search). 561 */ 562 ierr = VecCopy(Y,snes->vec_sol_update);CHKERRQ(ierr); 563 ynorm = 1; gnorm = vi->phinorm; 564 ierr = (*vi->LineSearch)(snes,vi->lsP,X,vi->phi,G,Y,W,vi->phinorm,xnorm,&ynorm,&gnorm,&lssucceed);CHKERRQ(ierr); 565 ierr = PetscInfo4(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lssucceed=%d\n",vi->phinorm,gnorm,ynorm,(int)lssucceed);CHKERRQ(ierr); 566 if (snes->reason == SNES_DIVERGED_FUNCTION_COUNT) break; 567 if (snes->domainerror) { 568 snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; 569 snes->ops->computefunction = vi->computeuserfunction; 570 PetscFunctionReturn(0); 571 } 572 if (!lssucceed) { 573 if (++snes->numFailures >= snes->maxFailures) { 574 PetscBool ismin; 575 snes->reason = SNES_DIVERGED_LINE_SEARCH; 576 ierr = SNESVICheckLocalMin_Private(snes,snes->jacobian,G,W,gnorm,&ismin);CHKERRQ(ierr); 577 if (ismin) snes->reason = SNES_DIVERGED_LOCAL_MIN; 578 break; 579 } 580 } 581 /* Update function and solution vectors */ 582 vi->phinorm = gnorm; 583 vi->merit = 0.5*vi->phinorm*vi->phinorm; 584 ierr = VecCopy(G,vi->phi);CHKERRQ(ierr); 585 ierr = VecCopy(W,X);CHKERRQ(ierr); 586 /* Monitor convergence */ 587 ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); 588 snes->iter = i+1; 589 snes->norm = vi->phinorm; 590 ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); 591 SNESLogConvHistory(snes,snes->norm,lits); 592 SNESMonitor(snes,snes->iter,snes->norm); 593 /* Test for convergence, xnorm = || X || */ 594 if (snes->ops->converged != SNESSkipConverged) { ierr = VecNorm(X,NORM_2,&xnorm);CHKERRQ(ierr); } 595 ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,vi->phinorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); 596 if (snes->reason) break; 597 } 598 if (i == maxits) { 599 ierr = PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",maxits);CHKERRQ(ierr); 600 if(!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT; 601 } 602 snes->ops->computefunction = vi->computeuserfunction; 603 PetscFunctionReturn(0); 604 } 605 606 #undef __FUNCT__ 607 #define __FUNCT__ "SNESVIGetActiveSetIS" 608 /* 609 SNESVIGetActiveSetIndices - Gets the global indices for the active set variables 610 611 Input parameter 612 . snes - the SNES context 613 . X - the snes solution vector 614 . F - the nonlinear function vector 615 616 Output parameter 617 . ISact - active set index set 618 */ 619 PetscErrorCode SNESVIGetActiveSetIS(SNES snes,Vec X,Vec F,IS* ISact) 620 { 621 PetscErrorCode ierr; 622 SNES_VI *vi = (SNES_VI*)snes->data; 623 Vec Xl=vi->xl,Xu=vi->xu; 624 const PetscScalar *x,*f,*xl,*xu; 625 PetscInt *idx_act,i,nlocal,nloc_isact=0,ilow,ihigh,i1=0; 626 627 PetscFunctionBegin; 628 ierr = VecGetLocalSize(X,&nlocal);CHKERRQ(ierr); 629 ierr = VecGetOwnershipRange(X,&ilow,&ihigh);CHKERRQ(ierr); 630 ierr = VecGetArrayRead(X,&x);CHKERRQ(ierr); 631 ierr = VecGetArrayRead(Xl,&xl);CHKERRQ(ierr); 632 ierr = VecGetArrayRead(Xu,&xu);CHKERRQ(ierr); 633 ierr = VecGetArrayRead(F,&f);CHKERRQ(ierr); 634 /* Compute active set size */ 635 for (i=0; i < nlocal;i++) { 636 if (!((x[i] > xl[i] + 1.e-8 || (f[i] < 0.0)) && ((x[i] < xu[i] - 1.e-8) || f[i] > 0.0))) nloc_isact++; 637 } 638 639 ierr = PetscMalloc(nloc_isact*sizeof(PetscInt),&idx_act);CHKERRQ(ierr); 640 641 /* Set active set indices */ 642 for(i=0; i < nlocal; i++) { 643 if (!((x[i] > xl[i] + 1.e-8 || (f[i] < 0.0)) && ((x[i] < xu[i] - 1.e-8) || f[i] > 0.0))) idx_act[i1++] = ilow+i; 644 } 645 646 /* Create active set IS */ 647 ierr = ISCreateGeneral(((PetscObject)snes)->comm,nloc_isact,idx_act,PETSC_OWN_POINTER,ISact);CHKERRQ(ierr); 648 649 ierr = VecRestoreArrayRead(X,&x);CHKERRQ(ierr); 650 ierr = VecRestoreArrayRead(Xl,&xl);CHKERRQ(ierr); 651 ierr = VecRestoreArrayRead(Xu,&xu);CHKERRQ(ierr); 652 ierr = VecRestoreArrayRead(F,&f);CHKERRQ(ierr); 653 PetscFunctionReturn(0); 654 } 655 656 #undef __FUNCT__ 657 #define __FUNCT__ "SNESVICreateIndexSets_RS" 658 PetscErrorCode SNESVICreateIndexSets_RS(SNES snes,Vec X,Vec F,IS* ISact,IS* ISinact) 659 { 660 PetscErrorCode ierr; 661 662 PetscFunctionBegin; 663 ierr = SNESVIGetActiveSetIS(snes,X,F,ISact);CHKERRQ(ierr); 664 ierr = ISComplement(*ISact,X->map->rstart,X->map->rend,ISinact);CHKERRQ(ierr); 665 PetscFunctionReturn(0); 666 } 667 668 /* Create active and inactive set vectors. The local size of this vector is set and petsc computes the global size */ 669 #undef __FUNCT__ 670 #define __FUNCT__ "SNESVICreateSubVectors" 671 PetscErrorCode SNESVICreateSubVectors(SNES snes,PetscInt n,Vec* newv) 672 { 673 PetscErrorCode ierr; 674 Vec v; 675 676 PetscFunctionBegin; 677 ierr = VecCreate(((PetscObject)snes)->comm,&v);CHKERRQ(ierr); 678 ierr = VecSetSizes(v,n,PETSC_DECIDE);CHKERRQ(ierr); 679 ierr = VecSetFromOptions(v);CHKERRQ(ierr); 680 *newv = v; 681 682 PetscFunctionReturn(0); 683 } 684 685 /* Resets the snes PC and KSP when the active set sizes change */ 686 #undef __FUNCT__ 687 #define __FUNCT__ "SNESVIResetPCandKSP" 688 PetscErrorCode SNESVIResetPCandKSP(SNES snes,Mat Amat,Mat Pmat) 689 { 690 PetscErrorCode ierr; 691 KSP kspnew,snesksp; 692 PC pcnew; 693 const MatSolverPackage stype; 694 695 PetscFunctionBegin; 696 /* The active and inactive set sizes have changed so need to create a new snes->ksp object */ 697 ierr = SNESGetKSP(snes,&snesksp);CHKERRQ(ierr); 698 ierr = KSPCreate(((PetscObject)snes)->comm,&kspnew);CHKERRQ(ierr); 699 /* Copy over snes->ksp info */ 700 kspnew->pc_side = snesksp->pc_side; 701 kspnew->rtol = snesksp->rtol; 702 kspnew->abstol = snesksp->abstol; 703 kspnew->max_it = snesksp->max_it; 704 ierr = KSPSetType(kspnew,((PetscObject)snesksp)->type_name);CHKERRQ(ierr); 705 ierr = KSPGetPC(kspnew,&pcnew);CHKERRQ(ierr); 706 ierr = PCSetType(kspnew->pc,((PetscObject)snesksp->pc)->type_name);CHKERRQ(ierr); 707 ierr = PCSetOperators(kspnew->pc,Amat,Pmat,DIFFERENT_NONZERO_PATTERN);CHKERRQ(ierr); 708 ierr = PCFactorGetMatSolverPackage(snesksp->pc,&stype);CHKERRQ(ierr); 709 ierr = PCFactorSetMatSolverPackage(kspnew->pc,stype);CHKERRQ(ierr); 710 ierr = KSPDestroy(snesksp);CHKERRQ(ierr); 711 snes->ksp = kspnew; 712 ierr = PetscLogObjectParent(snes,kspnew);CHKERRQ(ierr); 713 ierr = KSPSetFromOptions(kspnew);CHKERRQ(ierr); 714 PetscFunctionReturn(0); 715 } 716 717 718 #undef __FUNCT__ 719 #define __FUNCT__ "SNESVIComputeInactiveSetFnorm" 720 PetscErrorCode SNESVIComputeInactiveSetFnorm(SNES snes,Vec F,Vec X,PetscScalar *fnorm) 721 { 722 PetscErrorCode ierr; 723 SNES_VI *vi = (SNES_VI*)snes->data; 724 const PetscScalar *x,*xl,*xu,*f; 725 PetscInt i,n; 726 PetscReal rnorm; 727 728 PetscFunctionBegin; 729 ierr = VecGetLocalSize(X,&n);CHKERRQ(ierr); 730 ierr = VecGetArrayRead(vi->xl,&xl);CHKERRQ(ierr); 731 ierr = VecGetArrayRead(vi->xu,&xu);CHKERRQ(ierr); 732 ierr = VecGetArrayRead(X,&x);CHKERRQ(ierr); 733 ierr = VecGetArrayRead(F,&f);CHKERRQ(ierr); 734 rnorm = 0.0; 735 for (i=0; i<n; i++) { 736 if (((x[i] > xl[i] + 1.e-8 || (f[i] < 0.0)) && ((x[i] < xu[i] - 1.e-8) || f[i] > 0.0))) rnorm += f[i]*f[i]; 737 } 738 ierr = VecRestoreArrayRead(F,&f);CHKERRQ(ierr); 739 ierr = VecRestoreArrayRead(vi->xl,&xl);CHKERRQ(ierr); 740 ierr = VecRestoreArrayRead(vi->xu,&xu);CHKERRQ(ierr); 741 ierr = VecRestoreArrayRead(X,&x);CHKERRQ(ierr); 742 ierr = MPI_Allreduce(&rnorm,fnorm,1,MPIU_REAL,MPIU_SUM,((PetscObject)snes)->comm);CHKERRQ(ierr); 743 *fnorm = sqrt(*fnorm); 744 PetscFunctionReturn(0); 745 } 746 747 /* Variational Inequality solver using reduce space method. No semismooth algorithm is 748 implemented in this algorithm. It basically identifies the active variables and does 749 a linear solve on the inactive variables. */ 750 #undef __FUNCT__ 751 #define __FUNCT__ "SNESSolveVI_RS" 752 PetscErrorCode SNESSolveVI_RS(SNES snes) 753 { 754 SNES_VI *vi = (SNES_VI*)snes->data; 755 PetscErrorCode ierr; 756 PetscInt maxits,i,lits; 757 PetscBool lssucceed; 758 MatStructure flg = DIFFERENT_NONZERO_PATTERN; 759 PetscReal fnorm,gnorm,xnorm=0,ynorm; 760 Vec Y,X,F,G,W; 761 KSPConvergedReason kspreason; 762 763 PetscFunctionBegin; 764 snes->numFailures = 0; 765 snes->numLinearSolveFailures = 0; 766 snes->reason = SNES_CONVERGED_ITERATING; 767 768 maxits = snes->max_its; /* maximum number of iterations */ 769 X = snes->vec_sol; /* solution vector */ 770 F = snes->vec_func; /* residual vector */ 771 Y = snes->work[0]; /* work vectors */ 772 G = snes->work[1]; 773 W = snes->work[2]; 774 775 ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); 776 snes->iter = 0; 777 snes->norm = 0.0; 778 ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); 779 780 ierr = SNESVIProjectOntoBounds(snes,X);CHKERRQ(ierr); 781 ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); 782 if (snes->domainerror) { 783 snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; 784 PetscFunctionReturn(0); 785 } 786 ierr = SNESVIComputeInactiveSetFnorm(snes,F,X,&fnorm);CHKERRQ(ierr); 787 ierr = VecNormBegin(X,NORM_2,&xnorm);CHKERRQ(ierr); /* xnorm <- ||x|| */ 788 ierr = VecNormEnd(X,NORM_2,&xnorm);CHKERRQ(ierr); 789 if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 790 791 ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); 792 snes->norm = fnorm; 793 ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); 794 SNESLogConvHistory(snes,fnorm,0); 795 SNESMonitor(snes,0,fnorm); 796 797 /* set parameter for default relative tolerance convergence test */ 798 snes->ttol = fnorm*snes->rtol; 799 /* test convergence */ 800 ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); 801 if (snes->reason) PetscFunctionReturn(0); 802 803 for (i=0; i<maxits; i++) { 804 805 IS IS_act,IS_inact; /* _act -> active set _inact -> inactive set */ 806 VecScatter scat_act,scat_inact; 807 PetscInt nis_act,nis_inact; 808 Vec Y_act,Y_inact,F_inact; 809 Mat jac_inact_inact,prejac_inact_inact; 810 IS keptrows; 811 PetscBool isequal; 812 813 /* Call general purpose update function */ 814 if (snes->ops->update) { 815 ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr); 816 } 817 ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr); 818 819 /* Create active and inactive index sets */ 820 ierr = SNESVICreateIndexSets_RS(snes,X,F,&IS_act,&IS_inact);CHKERRQ(ierr); 821 822 /* Create inactive set submatrix */ 823 ierr = MatGetSubMatrix(snes->jacobian,IS_inact,IS_inact,MAT_INITIAL_MATRIX,&jac_inact_inact);CHKERRQ(ierr); 824 ierr = MatFindNonzeroRows(jac_inact_inact,&keptrows);CHKERRQ(ierr); 825 if (keptrows) { 826 PetscInt cnt,*nrows,k; 827 const PetscInt *krows,*inact; 828 PetscInt rstart=jac_inact_inact->rmap->rstart; 829 830 ierr = MatDestroy(jac_inact_inact);CHKERRQ(ierr); 831 ierr = ISDestroy(IS_act);CHKERRQ(ierr); 832 833 ierr = ISGetLocalSize(keptrows,&cnt);CHKERRQ(ierr); 834 ierr = ISGetIndices(keptrows,&krows);CHKERRQ(ierr); 835 ierr = ISGetIndices(IS_inact,&inact);CHKERRQ(ierr); 836 ierr = PetscMalloc(cnt*sizeof(PetscInt),&nrows);CHKERRQ(ierr); 837 for (k=0; k<cnt; k++) { 838 nrows[k] = inact[krows[k]-rstart]; 839 } 840 ierr = ISRestoreIndices(keptrows,&krows);CHKERRQ(ierr); 841 ierr = ISRestoreIndices(IS_inact,&inact);CHKERRQ(ierr); 842 ierr = ISDestroy(keptrows);CHKERRQ(ierr); 843 ierr = ISDestroy(IS_inact);CHKERRQ(ierr); 844 845 ierr = ISCreateGeneral(PETSC_COMM_WORLD,cnt,nrows,PETSC_OWN_POINTER,&IS_inact);CHKERRQ(ierr); 846 ierr = ISComplement(IS_inact,F->map->rstart,F->map->rend,&IS_act);CHKERRQ(ierr); 847 ierr = MatGetSubMatrix(snes->jacobian,IS_inact,IS_inact,MAT_INITIAL_MATRIX,&jac_inact_inact);CHKERRQ(ierr); 848 } 849 850 /* Get sizes of active and inactive sets */ 851 ierr = ISGetLocalSize(IS_act,&nis_act);CHKERRQ(ierr); 852 ierr = ISGetLocalSize(IS_inact,&nis_inact);CHKERRQ(ierr); 853 854 /* Create active and inactive set vectors */ 855 ierr = SNESVICreateSubVectors(snes,nis_inact,&F_inact);CHKERRQ(ierr); 856 ierr = SNESVICreateSubVectors(snes,nis_act,&Y_act);CHKERRQ(ierr); 857 ierr = SNESVICreateSubVectors(snes,nis_inact,&Y_inact);CHKERRQ(ierr); 858 859 /* Create scatter contexts */ 860 ierr = VecScatterCreate(Y,IS_act,Y_act,PETSC_NULL,&scat_act);CHKERRQ(ierr); 861 ierr = VecScatterCreate(Y,IS_inact,Y_inact,PETSC_NULL,&scat_inact);CHKERRQ(ierr); 862 863 /* Do a vec scatter to active and inactive set vectors */ 864 ierr = VecScatterBegin(scat_inact,F,F_inact,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 865 ierr = VecScatterEnd(scat_inact,F,F_inact,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 866 867 ierr = VecScatterBegin(scat_act,Y,Y_act,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 868 ierr = VecScatterEnd(scat_act,Y,Y_act,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 869 870 ierr = VecScatterBegin(scat_inact,Y,Y_inact,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 871 ierr = VecScatterEnd(scat_inact,Y,Y_inact,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 872 873 /* Active set direction = 0 */ 874 ierr = VecSet(Y_act,0);CHKERRQ(ierr); 875 if (snes->jacobian != snes->jacobian_pre) { 876 ierr = MatGetSubMatrix(snes->jacobian_pre,IS_inact,IS_inact,MAT_INITIAL_MATRIX,&prejac_inact_inact);CHKERRQ(ierr); 877 } else prejac_inact_inact = jac_inact_inact; 878 879 ierr = ISEqual(vi->IS_inact_prev,IS_inact,&isequal);CHKERRQ(ierr); 880 if (!isequal) { 881 ierr = SNESVIResetPCandKSP(snes,jac_inact_inact,prejac_inact_inact);CHKERRQ(ierr); 882 } 883 884 /* ierr = ISView(IS_inact,0);CHKERRQ(ierr); */ 885 /* ierr = ISView(IS_act,0);CHKERRQ(ierr);*/ 886 /* ierr = MatView(snes->jacobian_pre,0); */ 887 888 ierr = KSPSetOperators(snes->ksp,jac_inact_inact,prejac_inact_inact,flg);CHKERRQ(ierr); 889 ierr = KSPSetUp(snes->ksp);CHKERRQ(ierr); 890 { 891 PC pc; 892 PetscBool flg; 893 ierr = KSPGetPC(snes->ksp,&pc);CHKERRQ(ierr); 894 ierr = PetscTypeCompare((PetscObject)pc,PCFIELDSPLIT,&flg);CHKERRQ(ierr); 895 if (flg) { 896 KSP *subksps; 897 ierr = PCFieldSplitGetSubKSP(pc,PETSC_NULL,&subksps);CHKERRQ(ierr); 898 ierr = KSPGetPC(subksps[0],&pc);CHKERRQ(ierr); 899 ierr = PetscFree(subksps);CHKERRQ(ierr); 900 ierr = PetscTypeCompare((PetscObject)pc,PCBJACOBI,&flg);CHKERRQ(ierr); 901 if (flg) { 902 PetscInt n,N = 101*101,j,cnts[3] = {0,0,0}; 903 const PetscInt *ii; 904 905 ierr = ISGetSize(IS_inact,&n);CHKERRQ(ierr); 906 ierr = ISGetIndices(IS_inact,&ii);CHKERRQ(ierr); 907 for (j=0; j<n; j++) { 908 if (ii[j] < N) cnts[0]++; 909 else if (ii[j] < 2*N) cnts[1]++; 910 else if (ii[j] < 3*N) cnts[2]++; 911 } 912 ierr = ISRestoreIndices(IS_inact,&ii);CHKERRQ(ierr); 913 914 ierr = PCBJacobiSetTotalBlocks(pc,3,cnts);CHKERRQ(ierr); 915 } 916 } 917 } 918 919 ierr = SNES_KSPSolve(snes,snes->ksp,F_inact,Y_inact);CHKERRQ(ierr); 920 ierr = KSPGetConvergedReason(snes->ksp,&kspreason);CHKERRQ(ierr); 921 if (kspreason < 0) { 922 if (++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) { 923 ierr = PetscInfo2(snes,"iter=%D, number linear solve failures %D greater than current SNES allowed, stopping solve\n",snes->iter,snes->numLinearSolveFailures);CHKERRQ(ierr); 924 snes->reason = SNES_DIVERGED_LINEAR_SOLVE; 925 break; 926 } 927 } 928 929 ierr = VecScatterBegin(scat_act,Y_act,Y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 930 ierr = VecScatterEnd(scat_act,Y_act,Y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 931 ierr = VecScatterBegin(scat_inact,Y_inact,Y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 932 ierr = VecScatterEnd(scat_inact,Y_inact,Y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 933 934 ierr = VecDestroy(F_inact);CHKERRQ(ierr); 935 ierr = VecDestroy(Y_act);CHKERRQ(ierr); 936 ierr = VecDestroy(Y_inact);CHKERRQ(ierr); 937 ierr = VecScatterDestroy(scat_act);CHKERRQ(ierr); 938 ierr = VecScatterDestroy(scat_inact);CHKERRQ(ierr); 939 ierr = ISDestroy(IS_act);CHKERRQ(ierr); 940 if (!isequal) { 941 ierr = ISDestroy(vi->IS_inact_prev);CHKERRQ(ierr); 942 ierr = ISDuplicate(IS_inact,&vi->IS_inact_prev);CHKERRQ(ierr); 943 } 944 ierr = ISDestroy(IS_inact);CHKERRQ(ierr); 945 ierr = MatDestroy(jac_inact_inact);CHKERRQ(ierr); 946 if (snes->jacobian != snes->jacobian_pre) { 947 ierr = MatDestroy(prejac_inact_inact);CHKERRQ(ierr); 948 } 949 ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr); 950 snes->linear_its += lits; 951 ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr); 952 /* 953 if (vi->precheckstep) { 954 PetscBool changed_y = PETSC_FALSE; 955 ierr = (*vi->precheckstep)(snes,X,Y,vi->precheck,&changed_y);CHKERRQ(ierr); 956 } 957 958 if (PetscLogPrintInfo){ 959 ierr = SNESVICheckResidual_Private(snes,snes->jacobian,F,Y,G,W);CHKERRQ(ierr); 960 } 961 */ 962 /* Compute a (scaled) negative update in the line search routine: 963 Y <- X - lambda*Y 964 and evaluate G = function(Y) (depends on the line search). 965 */ 966 ierr = VecCopy(Y,snes->vec_sol_update);CHKERRQ(ierr); 967 ynorm = 1; gnorm = fnorm; 968 ierr = (*vi->LineSearch)(snes,vi->lsP,X,F,G,Y,W,fnorm,xnorm,&ynorm,&gnorm,&lssucceed);CHKERRQ(ierr); 969 ierr = PetscInfo4(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lssucceed=%d\n",fnorm,gnorm,ynorm,(int)lssucceed);CHKERRQ(ierr); 970 if (snes->reason == SNES_DIVERGED_FUNCTION_COUNT) break; 971 if (snes->domainerror) { 972 snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; 973 PetscFunctionReturn(0); 974 } 975 if (!lssucceed) { 976 if (++snes->numFailures >= snes->maxFailures) { 977 PetscBool ismin; 978 snes->reason = SNES_DIVERGED_LINE_SEARCH; 979 ierr = SNESVICheckLocalMin_Private(snes,snes->jacobian,G,W,gnorm,&ismin);CHKERRQ(ierr); 980 if (ismin) snes->reason = SNES_DIVERGED_LOCAL_MIN; 981 break; 982 } 983 } 984 /* Update function and solution vectors */ 985 fnorm = gnorm; 986 ierr = VecCopy(G,F);CHKERRQ(ierr); 987 ierr = VecCopy(W,X);CHKERRQ(ierr); 988 /* Monitor convergence */ 989 ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); 990 snes->iter = i+1; 991 snes->norm = fnorm; 992 ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); 993 SNESLogConvHistory(snes,snes->norm,lits); 994 SNESMonitor(snes,snes->iter,snes->norm); 995 /* Test for convergence, xnorm = || X || */ 996 if (snes->ops->converged != SNESSkipConverged) { ierr = VecNorm(X,NORM_2,&xnorm);CHKERRQ(ierr); } 997 ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); 998 if (snes->reason) break; 999 } 1000 if (i == maxits) { 1001 ierr = PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",maxits);CHKERRQ(ierr); 1002 if(!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT; 1003 } 1004 PetscFunctionReturn(0); 1005 } 1006 1007 #undef __FUNCT__ 1008 #define __FUNCT__ "SNESVISetRedundancyCheck" 1009 PetscErrorCode SNESVISetRedundancyCheck(SNES snes,PetscErrorCode (*func)(SNES,IS,IS*,void*)) 1010 { 1011 SNES_VI *vi = (SNES_VI*)snes->data; 1012 1013 PetscFunctionBegin; 1014 PetscValidHeaderSpecific(snes,SNES_CLASSID,1); 1015 vi->checkredundancy = func; 1016 PetscFunctionReturn(0); 1017 } 1018 1019 #if defined(PETSC_HAVE_MATLAB_ENGINE) 1020 #include <engine.h> 1021 #include <mex.h> 1022 typedef struct {char *funcname; mxArray *ctx;} SNESVIMatlabContext; 1023 1024 #undef __FUNCT__ 1025 #define __FUNCT__ "SNESVIRedundancyCheck_Matlab" 1026 PetscErrorCode SNESVIRedundancyCheck_Matlab(SNES snes,IS is_act,IS* is_redact,void* ctx) 1027 { 1028 PetscErrorCode ierr; 1029 SNESVIMatlabContext *sctx = (SNESVIMatlabContext*)ctx; 1030 int nlhs = 2, nrhs = 4; 1031 mxArray *plhs[2], *prhs[4]; 1032 long long int l1 = 0,ls = 0; 1033 1034 PetscFunctionBegin; 1035 PetscValidHeaderSpecific(snes,SNES_CLASSID,1); 1036 PetscValidHeaderSpecific(is_act,IS_CLASSID,2); 1037 PetscValidPointer(is_redact,3); 1038 PetscCheckSameComm(snes,1,is_act,2); 1039 1040 /* call Matlab function in ctx with arguments is_act */ 1041 ierr = PetscMemcpy(&ls,&snes,sizeof(snes));CHKERRQ(ierr); 1042 ierr = PetscMemcpy(&l1,&is_act,sizeof(is_act));CHKERRQ(ierr); 1043 prhs[0] = mxCreateDoubleScalar((double)ls); 1044 prhs[1] = mxCreateDoubleScalar((double)l1); 1045 prhs[2] = mxCreateString(sctx->funcname); 1046 prhs[3] = sctx->ctx; 1047 ierr = mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscSNESVIRedundancyCheckInternal");CHKERRQ(ierr); 1048 ierr = mxGetScalar(plhs[0]);CHKERRQ(ierr); 1049 *is_redact = (IS)mxGetPr(plhs[1]); 1050 mxDestroyArray(prhs[0]); 1051 mxDestroyArray(prhs[1]); 1052 mxDestroyArray(prhs[2]); 1053 mxDestroyArray(prhs[3]); 1054 mxDestroyArray(plhs[0]); 1055 PetscFunctionReturn(0); 1056 } 1057 1058 #undef __FUNCT__ 1059 #define __FUNCT__ "SNESVISetRedundancyCheckMatlab" 1060 PetscErrorCode SNESVISetRedundancyCheckMatlab(SNES snes,const char* func,mxArray* ctx) 1061 { 1062 PetscErrorCode ierr; 1063 SNESVIMatlabContext *sctx; 1064 SNES_VI *vi = (SNES_VI*)snes->data; 1065 1066 PetscFunctionBegin; 1067 /* currently sctx is memory bleed */ 1068 ierr = PetscMalloc(sizeof(SNESVIMatlabContext),&sctx);CHKERRQ(ierr); 1069 ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr); 1070 1071 sctx->ctx = mxDuplicateArray(ctx); 1072 vi->checkredundancy = SNESVIRedundancyCheck_Matlab; 1073 PetscFunctionReturn(0); 1074 } 1075 1076 #endif 1077 1078 1079 /* Variational Inequality solver using augmented space method. It does the opposite of the 1080 reduced space method i.e. it identifies the active set variables and instead of discarding 1081 them it augments the original system by introducing additional equality 1082 constraint equations for active set variables. The user can optionally provide an IS for 1083 a subset of 'redundant' active set variables which will treated as free variables. 1084 Specific implementation for Allen-Cahn problem 1085 */ 1086 #undef __FUNCT__ 1087 #define __FUNCT__ "SNESSolveVI_RS2" 1088 PetscErrorCode SNESSolveVI_RS2(SNES snes) 1089 { 1090 SNES_VI *vi = (SNES_VI*)snes->data; 1091 PetscErrorCode ierr; 1092 PetscInt maxits,i,lits; 1093 PetscBool lssucceed; 1094 MatStructure flg = DIFFERENT_NONZERO_PATTERN; 1095 PetscReal fnorm,gnorm,xnorm=0,ynorm; 1096 Vec Y,X,F,G,W; 1097 KSPConvergedReason kspreason; 1098 1099 PetscFunctionBegin; 1100 snes->numFailures = 0; 1101 snes->numLinearSolveFailures = 0; 1102 snes->reason = SNES_CONVERGED_ITERATING; 1103 1104 maxits = snes->max_its; /* maximum number of iterations */ 1105 X = snes->vec_sol; /* solution vector */ 1106 F = snes->vec_func; /* residual vector */ 1107 Y = snes->work[0]; /* work vectors */ 1108 G = snes->work[1]; 1109 W = snes->work[2]; 1110 1111 ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); 1112 snes->iter = 0; 1113 snes->norm = 0.0; 1114 ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); 1115 1116 ierr = SNESVIProjectOntoBounds(snes,X);CHKERRQ(ierr); 1117 ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); 1118 if (snes->domainerror) { 1119 snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; 1120 PetscFunctionReturn(0); 1121 } 1122 ierr = SNESVIComputeInactiveSetFnorm(snes,F,X,&fnorm);CHKERRQ(ierr); 1123 ierr = VecNormBegin(X,NORM_2,&xnorm);CHKERRQ(ierr); /* xnorm <- ||x|| */ 1124 ierr = VecNormEnd(X,NORM_2,&xnorm);CHKERRQ(ierr); 1125 if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1126 1127 ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); 1128 snes->norm = fnorm; 1129 ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); 1130 SNESLogConvHistory(snes,fnorm,0); 1131 SNESMonitor(snes,0,fnorm); 1132 1133 /* set parameter for default relative tolerance convergence test */ 1134 snes->ttol = fnorm*snes->rtol; 1135 /* test convergence */ 1136 ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); 1137 if (snes->reason) PetscFunctionReturn(0); 1138 1139 for (i=0; i<maxits; i++) { 1140 IS IS_act,IS_inact; /* _act -> active set _inact -> inactive set */ 1141 IS IS_redact=PETSC_NULL; /* redundant active set */ 1142 Mat J_aug,Jpre_aug; 1143 Vec F_aug,Y_aug; 1144 PetscInt nis_redact,nis_act; 1145 const PetscInt *idx_redact,*idx_act; 1146 PetscInt k; 1147 PetscInt *idx_actkept=PETSC_NULL,nkept=0; /* list of kept active set */ 1148 PetscScalar *f,*f2; 1149 PetscBool isequal; 1150 PetscInt i1=0,j1=0; 1151 1152 /* Call general purpose update function */ 1153 if (snes->ops->update) { 1154 ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr); 1155 } 1156 ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr); 1157 1158 /* Create active and inactive index sets */ 1159 ierr = SNESVICreateIndexSets_RS(snes,X,F,&IS_act,&IS_inact);CHKERRQ(ierr); 1160 1161 /* Get local active set size */ 1162 ierr = ISGetLocalSize(IS_act,&nis_act);CHKERRQ(ierr); 1163 ierr = ISGetIndices(IS_act,&idx_act);CHKERRQ(ierr); 1164 if(nis_act) { 1165 if(vi->checkredundancy) { 1166 (*vi->checkredundancy)(snes,IS_act,&IS_redact,snes->funP); 1167 } 1168 1169 if(!IS_redact) { 1170 /* User called checkredundancy function but didn't create IS_redact because 1171 there were no redundant active set variables */ 1172 /* Copy over all active set indices to the list */ 1173 ierr = PetscMalloc(nis_act*sizeof(PetscInt),&idx_actkept);CHKERRQ(ierr); 1174 for(k=0;k < nis_act;k++) idx_actkept[k] = idx_act[k]; 1175 nkept = nis_act; 1176 } else { 1177 ierr = ISGetLocalSize(IS_redact,&nis_redact);CHKERRQ(ierr); 1178 ierr = PetscMalloc((nis_act-nis_redact)*sizeof(PetscInt),&idx_actkept);CHKERRQ(ierr); 1179 1180 /* Create reduced active set list */ 1181 ierr = ISGetIndices(IS_act,&idx_act);CHKERRQ(ierr); 1182 ierr = ISGetIndices(IS_redact,&idx_redact);CHKERRQ(ierr); 1183 j1 = 0; 1184 for(k=0;k<nis_act;k++) { 1185 if(j1 < nis_redact && idx_act[k] == idx_redact[j1]) j1++; 1186 else idx_actkept[nkept++] = idx_act[k]; 1187 } 1188 ierr = ISRestoreIndices(IS_act,&idx_act);CHKERRQ(ierr); 1189 ierr = ISRestoreIndices(IS_redact,&idx_redact);CHKERRQ(ierr); 1190 } 1191 1192 /* Create augmented F and Y */ 1193 ierr = VecCreate(((PetscObject)snes)->comm,&F_aug);CHKERRQ(ierr); 1194 ierr = VecSetSizes(F_aug,F->map->n+nkept,PETSC_DECIDE);CHKERRQ(ierr); 1195 ierr = VecSetFromOptions(F_aug);CHKERRQ(ierr); 1196 ierr = VecDuplicate(F_aug,&Y_aug);CHKERRQ(ierr); 1197 1198 /* Copy over F to F_aug in the first n locations */ 1199 ierr = VecGetArray(F,&f);CHKERRQ(ierr); 1200 ierr = VecGetArray(F_aug,&f2);CHKERRQ(ierr); 1201 ierr = PetscMemcpy(f2,f,F->map->n*sizeof(PetscScalar));CHKERRQ(ierr); 1202 ierr = VecRestoreArray(F,&f);CHKERRQ(ierr); 1203 ierr = VecRestoreArray(F_aug,&f2);CHKERRQ(ierr); 1204 1205 /* Create the augmented jacobian matrix */ 1206 ierr = MatCreate(((PetscObject)snes)->comm,&J_aug);CHKERRQ(ierr); 1207 ierr = MatSetSizes(J_aug,X->map->n+nkept,X->map->n+nkept,PETSC_DECIDE,PETSC_DECIDE);CHKERRQ(ierr); 1208 ierr = MatSetFromOptions(J_aug);CHKERRQ(ierr); 1209 1210 1211 { /* local vars */ 1212 /* Preallocate augmented matrix and set values in it...Doing only sequential case first*/ 1213 PetscInt ncols; 1214 const PetscInt *cols; 1215 const PetscScalar *vals; 1216 PetscScalar value=1.0; 1217 PetscInt row,col; 1218 PetscInt *d_nnz; 1219 1220 ierr = PetscMalloc((X->map->n+nkept)*sizeof(PetscInt),&d_nnz);CHKERRQ(ierr); 1221 ierr = PetscMemzero(d_nnz,(X->map->n+nkept)*sizeof(PetscInt));CHKERRQ(ierr); 1222 for(row=0;row<snes->jacobian->rmap->n;row++) { 1223 ierr = MatGetRow(snes->jacobian,row,&ncols,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr); 1224 d_nnz[row] += ncols; 1225 ierr = MatRestoreRow(snes->jacobian,row,&ncols,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr); 1226 } 1227 1228 for(k=0;k<nkept;k++) { 1229 d_nnz[idx_actkept[k]] += 1; 1230 d_nnz[snes->jacobian->rmap->n+k] += 1; 1231 } 1232 ierr = MatSeqAIJSetPreallocation(J_aug,PETSC_NULL,d_nnz);CHKERRQ(ierr); 1233 1234 ierr = PetscFree(d_nnz);CHKERRQ(ierr); 1235 1236 /* Set the original jacobian matrix in J_aug */ 1237 for(row=0;row<snes->jacobian->rmap->n;row++) { 1238 ierr = MatGetRow(snes->jacobian,row,&ncols,&cols,&vals);CHKERRQ(ierr); 1239 ierr = MatSetValues(J_aug,1,&row,ncols,cols,vals,INSERT_VALUES);CHKERRQ(ierr); 1240 ierr = MatRestoreRow(snes->jacobian,row,&ncols,&cols,&vals);CHKERRQ(ierr); 1241 } 1242 /* Add the augmented part */ 1243 for(k=0;k<nkept;k++) { 1244 row = idx_actkept[k]; 1245 col = snes->jacobian->rmap->n+k; 1246 ierr = MatSetValues(J_aug,1,&row,1,&col,&value,INSERT_VALUES);CHKERRQ(ierr); 1247 ierr = MatSetValues(J_aug,1,&col,1,&row,&value,INSERT_VALUES);CHKERRQ(ierr); 1248 } 1249 ierr = MatAssemblyBegin(J_aug,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 1250 ierr = MatAssemblyEnd(J_aug,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 1251 /* Only considering prejac = jac for now */ 1252 Jpre_aug = J_aug; 1253 } /* local vars*/ 1254 } else { 1255 F_aug = F; J_aug = snes->jacobian; Y_aug = Y; Jpre_aug = snes->jacobian_pre; 1256 } 1257 1258 ierr = ISEqual(vi->IS_inact_prev,IS_inact,&isequal);CHKERRQ(ierr); 1259 if (!isequal) { 1260 ierr = SNESVIResetPCandKSP(snes,J_aug,Jpre_aug);CHKERRQ(ierr); 1261 } 1262 ierr = KSPSetOperators(snes->ksp,J_aug,Jpre_aug,flg);CHKERRQ(ierr); 1263 ierr = KSPSetUp(snes->ksp);CHKERRQ(ierr); 1264 /* { 1265 PC pc; 1266 PetscBool flg; 1267 ierr = KSPGetPC(snes->ksp,&pc);CHKERRQ(ierr); 1268 ierr = PetscTypeCompare((PetscObject)pc,PCFIELDSPLIT,&flg);CHKERRQ(ierr); 1269 if (flg) { 1270 KSP *subksps; 1271 ierr = PCFieldSplitGetSubKSP(pc,PETSC_NULL,&subksps);CHKERRQ(ierr); 1272 ierr = KSPGetPC(subksps[0],&pc);CHKERRQ(ierr); 1273 ierr = PetscFree(subksps);CHKERRQ(ierr); 1274 ierr = PetscTypeCompare((PetscObject)pc,PCBJACOBI,&flg);CHKERRQ(ierr); 1275 if (flg) { 1276 PetscInt n,N = 101*101,j,cnts[3] = {0,0,0}; 1277 const PetscInt *ii; 1278 1279 ierr = ISGetSize(IS_inact,&n);CHKERRQ(ierr); 1280 ierr = ISGetIndices(IS_inact,&ii);CHKERRQ(ierr); 1281 for (j=0; j<n; j++) { 1282 if (ii[j] < N) cnts[0]++; 1283 else if (ii[j] < 2*N) cnts[1]++; 1284 else if (ii[j] < 3*N) cnts[2]++; 1285 } 1286 ierr = ISRestoreIndices(IS_inact,&ii);CHKERRQ(ierr); 1287 1288 ierr = PCBJacobiSetTotalBlocks(pc,3,cnts);CHKERRQ(ierr); 1289 } 1290 } 1291 } 1292 */ 1293 ierr = SNES_KSPSolve(snes,snes->ksp,F_aug,Y_aug);CHKERRQ(ierr); 1294 ierr = KSPGetConvergedReason(snes->ksp,&kspreason);CHKERRQ(ierr); 1295 if (kspreason < 0) { 1296 if (++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) { 1297 ierr = PetscInfo2(snes,"iter=%D, number linear solve failures %D greater than current SNES allowed, stopping solve\n",snes->iter,snes->numLinearSolveFailures);CHKERRQ(ierr); 1298 snes->reason = SNES_DIVERGED_LINEAR_SOLVE; 1299 break; 1300 } 1301 } 1302 1303 if(nis_act) { 1304 PetscScalar *y1,*y2; 1305 ierr = VecGetArray(Y,&y1);CHKERRQ(ierr); 1306 ierr = VecGetArray(Y_aug,&y2);CHKERRQ(ierr); 1307 /* Copy over inactive Y_aug to Y */ 1308 j1 = 0; 1309 for(i1=Y->map->rstart;i1 < Y->map->rend;i1++) { 1310 if(j1 < nkept && idx_actkept[j1] == i1) j1++; 1311 else y1[i1-Y->map->rstart] = y2[i1-Y->map->rstart]; 1312 } 1313 ierr = VecRestoreArray(Y,&y1);CHKERRQ(ierr); 1314 ierr = VecRestoreArray(Y_aug,&y2);CHKERRQ(ierr); 1315 1316 ierr = VecDestroy(F_aug);CHKERRQ(ierr); 1317 ierr = VecDestroy(Y_aug);CHKERRQ(ierr); 1318 ierr = MatDestroy(J_aug);CHKERRQ(ierr); 1319 ierr = PetscFree(idx_actkept);CHKERRQ(ierr); 1320 } 1321 1322 if (!isequal) { 1323 ierr = ISDestroy(vi->IS_inact_prev);CHKERRQ(ierr); 1324 ierr = ISDuplicate(IS_inact,&vi->IS_inact_prev);CHKERRQ(ierr); 1325 } 1326 ierr = ISDestroy(IS_inact);CHKERRQ(ierr); 1327 1328 ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr); 1329 snes->linear_its += lits; 1330 ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr); 1331 /* 1332 if (vi->precheckstep) { 1333 PetscBool changed_y = PETSC_FALSE; 1334 ierr = (*vi->precheckstep)(snes,X,Y,vi->precheck,&changed_y);CHKERRQ(ierr); 1335 } 1336 1337 if (PetscLogPrintInfo){ 1338 ierr = SNESVICheckResidual_Private(snes,snes->jacobian,F,Y,G,W);CHKERRQ(ierr); 1339 } 1340 */ 1341 /* Compute a (scaled) negative update in the line search routine: 1342 Y <- X - lambda*Y 1343 and evaluate G = function(Y) (depends on the line search). 1344 */ 1345 ierr = VecCopy(Y,snes->vec_sol_update);CHKERRQ(ierr); 1346 ynorm = 1; gnorm = fnorm; 1347 ierr = (*vi->LineSearch)(snes,vi->lsP,X,F,G,Y,W,fnorm,xnorm,&ynorm,&gnorm,&lssucceed);CHKERRQ(ierr); 1348 ierr = PetscInfo4(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lssucceed=%d\n",fnorm,gnorm,ynorm,(int)lssucceed);CHKERRQ(ierr); 1349 if (snes->reason == SNES_DIVERGED_FUNCTION_COUNT) break; 1350 if (snes->domainerror) { 1351 snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; 1352 PetscFunctionReturn(0); 1353 } 1354 if (!lssucceed) { 1355 if (++snes->numFailures >= snes->maxFailures) { 1356 PetscBool ismin; 1357 snes->reason = SNES_DIVERGED_LINE_SEARCH; 1358 ierr = SNESVICheckLocalMin_Private(snes,snes->jacobian,G,W,gnorm,&ismin);CHKERRQ(ierr); 1359 if (ismin) snes->reason = SNES_DIVERGED_LOCAL_MIN; 1360 break; 1361 } 1362 } 1363 /* Update function and solution vectors */ 1364 fnorm = gnorm; 1365 ierr = VecCopy(G,F);CHKERRQ(ierr); 1366 ierr = VecCopy(W,X);CHKERRQ(ierr); 1367 /* Monitor convergence */ 1368 ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); 1369 snes->iter = i+1; 1370 snes->norm = fnorm; 1371 ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); 1372 SNESLogConvHistory(snes,snes->norm,lits); 1373 SNESMonitor(snes,snes->iter,snes->norm); 1374 /* Test for convergence, xnorm = || X || */ 1375 if (snes->ops->converged != SNESSkipConverged) { ierr = VecNorm(X,NORM_2,&xnorm);CHKERRQ(ierr); } 1376 ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); 1377 if (snes->reason) break; 1378 } 1379 if (i == maxits) { 1380 ierr = PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",maxits);CHKERRQ(ierr); 1381 if(!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT; 1382 } 1383 PetscFunctionReturn(0); 1384 } 1385 1386 /* -------------------------------------------------------------------------- */ 1387 /* 1388 SNESSetUp_VI - Sets up the internal data structures for the later use 1389 of the SNESVI nonlinear solver. 1390 1391 Input Parameter: 1392 . snes - the SNES context 1393 . x - the solution vector 1394 1395 Application Interface Routine: SNESSetUp() 1396 1397 Notes: 1398 For basic use of the SNES solvers, the user need not explicitly call 1399 SNESSetUp(), since these actions will automatically occur during 1400 the call to SNESSolve(). 1401 */ 1402 #undef __FUNCT__ 1403 #define __FUNCT__ "SNESSetUp_VI" 1404 PetscErrorCode SNESSetUp_VI(SNES snes) 1405 { 1406 PetscErrorCode ierr; 1407 SNES_VI *vi = (SNES_VI*) snes->data; 1408 PetscInt i_start[3],i_end[3]; 1409 1410 PetscFunctionBegin; 1411 1412 ierr = SNESDefaultGetWork(snes,3);CHKERRQ(ierr); 1413 1414 /* If the lower and upper bound on variables are not set, set it to 1415 -Inf and Inf */ 1416 if (!vi->xl && !vi->xu) { 1417 vi->usersetxbounds = PETSC_FALSE; 1418 ierr = VecDuplicate(snes->vec_sol, &vi->xl); CHKERRQ(ierr); 1419 ierr = VecSet(vi->xl,PETSC_VI_NINF);CHKERRQ(ierr); 1420 ierr = VecDuplicate(snes->vec_sol, &vi->xu); CHKERRQ(ierr); 1421 ierr = VecSet(vi->xu,PETSC_VI_INF);CHKERRQ(ierr); 1422 } else { 1423 /* Check if lower bound, upper bound and solution vector distribution across the processors is identical */ 1424 ierr = VecGetOwnershipRange(snes->vec_sol,i_start,i_end);CHKERRQ(ierr); 1425 ierr = VecGetOwnershipRange(vi->xl,i_start+1,i_end+1);CHKERRQ(ierr); 1426 ierr = VecGetOwnershipRange(vi->xu,i_start+2,i_end+2);CHKERRQ(ierr); 1427 if ((i_start[0] != i_start[1]) || (i_start[0] != i_start[2]) || (i_end[0] != i_end[1]) || (i_end[0] != i_end[2])) 1428 SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Distribution of lower bound, upper bound and the solution vector should be identical across all the processors."); 1429 } 1430 if (snes->ops->solve != SNESSolveVI_SS) { 1431 /* Set up previous active index set for the first snes solve 1432 vi->IS_inact_prev = 0,1,2,....N */ 1433 PetscInt *indices; 1434 PetscInt i,n,rstart,rend; 1435 1436 ierr = VecGetOwnershipRange(snes->vec_sol,&rstart,&rend);CHKERRQ(ierr); 1437 ierr = VecGetLocalSize(snes->vec_sol,&n);CHKERRQ(ierr); 1438 ierr = PetscMalloc(n*sizeof(PetscInt),&indices);CHKERRQ(ierr); 1439 for(i=0;i < n; i++) indices[i] = rstart + i; 1440 ierr = ISCreateGeneral(((PetscObject)snes)->comm,n,indices,PETSC_OWN_POINTER,&vi->IS_inact_prev); 1441 } 1442 1443 if (snes->ops->solve == SNESSolveVI_SS) { 1444 ierr = VecDuplicate(snes->vec_sol, &vi->dpsi);CHKERRQ(ierr); 1445 ierr = VecDuplicate(snes->vec_sol, &vi->phi); CHKERRQ(ierr); 1446 ierr = VecDuplicate(snes->vec_sol, &vi->Da); CHKERRQ(ierr); 1447 ierr = VecDuplicate(snes->vec_sol, &vi->Db); CHKERRQ(ierr); 1448 ierr = VecDuplicate(snes->vec_sol, &vi->z);CHKERRQ(ierr); 1449 ierr = VecDuplicate(snes->vec_sol, &vi->t); CHKERRQ(ierr); 1450 } 1451 PetscFunctionReturn(0); 1452 } 1453 /* -------------------------------------------------------------------------- */ 1454 /* 1455 SNESDestroy_VI - Destroys the private SNES_VI context that was created 1456 with SNESCreate_VI(). 1457 1458 Input Parameter: 1459 . snes - the SNES context 1460 1461 Application Interface Routine: SNESDestroy() 1462 */ 1463 #undef __FUNCT__ 1464 #define __FUNCT__ "SNESDestroy_VI" 1465 PetscErrorCode SNESDestroy_VI(SNES snes) 1466 { 1467 SNES_VI *vi = (SNES_VI*) snes->data; 1468 PetscErrorCode ierr; 1469 1470 PetscFunctionBegin; 1471 if (snes->ops->solve != SNESSolveVI_SS) { 1472 ierr = ISDestroy(vi->IS_inact_prev); 1473 } 1474 1475 if (snes->ops->solve == SNESSolveVI_SS) { 1476 /* clear vectors */ 1477 ierr = VecDestroy(vi->dpsi);CHKERRQ(ierr); 1478 ierr = VecDestroy(vi->phi); CHKERRQ(ierr); 1479 ierr = VecDestroy(vi->Da); CHKERRQ(ierr); 1480 ierr = VecDestroy(vi->Db); CHKERRQ(ierr); 1481 ierr = VecDestroy(vi->z); CHKERRQ(ierr); 1482 ierr = VecDestroy(vi->t); CHKERRQ(ierr); 1483 } 1484 1485 if (!vi->usersetxbounds) { 1486 ierr = VecDestroy(vi->xl); CHKERRQ(ierr); 1487 ierr = VecDestroy(vi->xu); CHKERRQ(ierr); 1488 } 1489 1490 if (vi->lsmonitor) { 1491 ierr = PetscViewerASCIIMonitorDestroy(vi->lsmonitor);CHKERRQ(ierr); 1492 } 1493 ierr = PetscFree(snes->data);CHKERRQ(ierr); 1494 1495 /* clear composed functions */ 1496 ierr = PetscObjectComposeFunctionDynamic((PetscObject)snes,"SNESLineSearchSet_C","",PETSC_NULL);CHKERRQ(ierr); 1497 ierr = PetscObjectComposeFunctionDynamic((PetscObject)snes,"SNESLineSearchSetMonitor_C","",PETSC_NULL);CHKERRQ(ierr); 1498 PetscFunctionReturn(0); 1499 } 1500 1501 /* -------------------------------------------------------------------------- */ 1502 #undef __FUNCT__ 1503 #define __FUNCT__ "SNESLineSearchNo_VI" 1504 1505 /* 1506 This routine does not actually do a line search but it takes a full newton 1507 step while ensuring that the new iterates remain within the constraints. 1508 1509 */ 1510 PetscErrorCode SNESLineSearchNo_VI(SNES snes,void *lsctx,Vec x,Vec f,Vec g,Vec y,Vec w,PetscReal fnorm,PetscReal xnorm,PetscReal *ynorm,PetscReal *gnorm,PetscBool *flag) 1511 { 1512 PetscErrorCode ierr; 1513 SNES_VI *vi = (SNES_VI*)snes->data; 1514 PetscBool changed_w = PETSC_FALSE,changed_y = PETSC_FALSE; 1515 1516 PetscFunctionBegin; 1517 *flag = PETSC_TRUE; 1518 ierr = PetscLogEventBegin(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1519 ierr = VecNorm(y,NORM_2,ynorm);CHKERRQ(ierr); /* ynorm = || y || */ 1520 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); /* w <- x - y */ 1521 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1522 if (vi->postcheckstep) { 1523 ierr = (*vi->postcheckstep)(snes,x,y,w,vi->postcheck,&changed_y,&changed_w);CHKERRQ(ierr); 1524 } 1525 if (changed_y) { 1526 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); /* w <- x - y */ 1527 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1528 } 1529 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1530 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1531 if (!snes->domainerror) { 1532 if (snes->ops->solve != SNESSolveVI_SS) { 1533 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1534 } else { 1535 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); /* gnorm = || g || */ 1536 } 1537 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1538 } 1539 if (vi->lsmonitor) { 1540 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Using full step: fnorm %G gnorm %G\n",fnorm,*gnorm);CHKERRQ(ierr); 1541 } 1542 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1543 PetscFunctionReturn(0); 1544 } 1545 1546 /* -------------------------------------------------------------------------- */ 1547 #undef __FUNCT__ 1548 #define __FUNCT__ "SNESLineSearchNoNorms_VI" 1549 1550 /* 1551 This routine is a copy of SNESLineSearchNoNorms in snes/impls/ls/ls.c 1552 */ 1553 PetscErrorCode SNESLineSearchNoNorms_VI(SNES snes,void *lsctx,Vec x,Vec f,Vec g,Vec y,Vec w,PetscReal fnorm,PetscReal xnorm,PetscReal *ynorm,PetscReal *gnorm,PetscBool *flag) 1554 { 1555 PetscErrorCode ierr; 1556 SNES_VI *vi = (SNES_VI*)snes->data; 1557 PetscBool changed_w = PETSC_FALSE,changed_y = PETSC_FALSE; 1558 1559 PetscFunctionBegin; 1560 *flag = PETSC_TRUE; 1561 ierr = PetscLogEventBegin(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1562 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); /* w <- x - y */ 1563 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1564 if (vi->postcheckstep) { 1565 ierr = (*vi->postcheckstep)(snes,x,y,w,vi->postcheck,&changed_y,&changed_w);CHKERRQ(ierr); 1566 } 1567 if (changed_y) { 1568 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); /* w <- x - y */ 1569 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1570 } 1571 1572 /* don't evaluate function the last time through */ 1573 if (snes->iter < snes->max_its-1) { 1574 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1575 } 1576 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1577 PetscFunctionReturn(0); 1578 } 1579 1580 /* -------------------------------------------------------------------------- */ 1581 #undef __FUNCT__ 1582 #define __FUNCT__ "SNESLineSearchCubic_VI" 1583 /* 1584 This routine implements a cubic line search while doing a projection on the variable bounds 1585 */ 1586 PetscErrorCode SNESLineSearchCubic_VI(SNES snes,void *lsctx,Vec x,Vec f,Vec g,Vec y,Vec w,PetscReal fnorm,PetscReal xnorm,PetscReal *ynorm,PetscReal *gnorm,PetscBool *flag) 1587 { 1588 PetscReal initslope,lambdaprev,gnormprev,a,b,d,t1,t2,rellength; 1589 PetscReal minlambda,lambda,lambdatemp; 1590 #if defined(PETSC_USE_COMPLEX) 1591 PetscScalar cinitslope; 1592 #endif 1593 PetscErrorCode ierr; 1594 PetscInt count; 1595 SNES_VI *vi = (SNES_VI*)snes->data; 1596 PetscBool changed_w = PETSC_FALSE,changed_y = PETSC_FALSE; 1597 MPI_Comm comm; 1598 1599 PetscFunctionBegin; 1600 ierr = PetscObjectGetComm((PetscObject)snes,&comm);CHKERRQ(ierr); 1601 ierr = PetscLogEventBegin(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1602 *flag = PETSC_TRUE; 1603 1604 ierr = VecNorm(y,NORM_2,ynorm);CHKERRQ(ierr); 1605 if (*ynorm == 0.0) { 1606 if (vi->lsmonitor) { 1607 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Initial direction and size is 0\n");CHKERRQ(ierr); 1608 } 1609 *gnorm = fnorm; 1610 ierr = VecCopy(x,w);CHKERRQ(ierr); 1611 ierr = VecCopy(f,g);CHKERRQ(ierr); 1612 *flag = PETSC_FALSE; 1613 goto theend1; 1614 } 1615 if (*ynorm > vi->maxstep) { /* Step too big, so scale back */ 1616 if (vi->lsmonitor) { 1617 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Scaling step by %G old ynorm %G\n",vi->maxstep/(*ynorm),*ynorm);CHKERRQ(ierr); 1618 } 1619 ierr = VecScale(y,vi->maxstep/(*ynorm));CHKERRQ(ierr); 1620 *ynorm = vi->maxstep; 1621 } 1622 ierr = VecMaxPointwiseDivide(y,x,&rellength);CHKERRQ(ierr); 1623 minlambda = vi->minlambda/rellength; 1624 ierr = MatMult(snes->jacobian,y,w);CHKERRQ(ierr); 1625 #if defined(PETSC_USE_COMPLEX) 1626 ierr = VecDot(f,w,&cinitslope);CHKERRQ(ierr); 1627 initslope = PetscRealPart(cinitslope); 1628 #else 1629 ierr = VecDot(f,w,&initslope);CHKERRQ(ierr); 1630 #endif 1631 if (initslope > 0.0) initslope = -initslope; 1632 if (initslope == 0.0) initslope = -1.0; 1633 1634 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); 1635 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1636 if (snes->nfuncs >= snes->max_funcs) { 1637 ierr = PetscInfo(snes,"Exceeded maximum function evaluations, while checking full step length!\n");CHKERRQ(ierr); 1638 *flag = PETSC_FALSE; 1639 snes->reason = SNES_DIVERGED_FUNCTION_COUNT; 1640 goto theend1; 1641 } 1642 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1643 if (snes->ops->solve != SNESSolveVI_SS) { 1644 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1645 } else { 1646 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1647 } 1648 if (snes->domainerror) { 1649 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1650 PetscFunctionReturn(0); 1651 } 1652 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1653 ierr = PetscInfo2(snes,"Initial fnorm %G gnorm %G\n",fnorm,*gnorm);CHKERRQ(ierr); 1654 if (.5*(*gnorm)*(*gnorm) <= .5*fnorm*fnorm + vi->alpha*initslope) { /* Sufficient reduction */ 1655 if (vi->lsmonitor) { 1656 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Using full step: fnorm %G gnorm %G\n",fnorm,*gnorm);CHKERRQ(ierr); 1657 } 1658 goto theend1; 1659 } 1660 1661 /* Fit points with quadratic */ 1662 lambda = 1.0; 1663 lambdatemp = -initslope/((*gnorm)*(*gnorm) - fnorm*fnorm - 2.0*initslope); 1664 lambdaprev = lambda; 1665 gnormprev = *gnorm; 1666 if (lambdatemp > .5*lambda) lambdatemp = .5*lambda; 1667 if (lambdatemp <= .1*lambda) lambda = .1*lambda; 1668 else lambda = lambdatemp; 1669 1670 ierr = VecWAXPY(w,-lambda,y,x);CHKERRQ(ierr); 1671 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1672 if (snes->nfuncs >= snes->max_funcs) { 1673 ierr = PetscInfo1(snes,"Exceeded maximum function evaluations, while attempting quadratic backtracking! %D \n",snes->nfuncs);CHKERRQ(ierr); 1674 *flag = PETSC_FALSE; 1675 snes->reason = SNES_DIVERGED_FUNCTION_COUNT; 1676 goto theend1; 1677 } 1678 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1679 if (snes->ops->solve != SNESSolveVI_SS) { 1680 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1681 } else { 1682 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1683 } 1684 if (snes->domainerror) { 1685 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1686 PetscFunctionReturn(0); 1687 } 1688 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1689 if (vi->lsmonitor) { 1690 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: gnorm after quadratic fit %G\n",*gnorm);CHKERRQ(ierr); 1691 } 1692 if (.5*(*gnorm)*(*gnorm) < .5*fnorm*fnorm + lambda*vi->alpha*initslope) { /* sufficient reduction */ 1693 if (vi->lsmonitor) { 1694 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Quadratically determined step, lambda=%18.16e\n",lambda);CHKERRQ(ierr); 1695 } 1696 goto theend1; 1697 } 1698 1699 /* Fit points with cubic */ 1700 count = 1; 1701 while (PETSC_TRUE) { 1702 if (lambda <= minlambda) { 1703 if (vi->lsmonitor) { 1704 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: unable to find good step length! After %D tries \n",count);CHKERRQ(ierr); 1705 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, minlambda=%18.16e, lambda=%18.16e, initial slope=%18.16e\n",fnorm,*gnorm,*ynorm,minlambda,lambda,initslope);CHKERRQ(ierr); 1706 } 1707 *flag = PETSC_FALSE; 1708 break; 1709 } 1710 t1 = .5*((*gnorm)*(*gnorm) - fnorm*fnorm) - lambda*initslope; 1711 t2 = .5*(gnormprev*gnormprev - fnorm*fnorm) - lambdaprev*initslope; 1712 a = (t1/(lambda*lambda) - t2/(lambdaprev*lambdaprev))/(lambda-lambdaprev); 1713 b = (-lambdaprev*t1/(lambda*lambda) + lambda*t2/(lambdaprev*lambdaprev))/(lambda-lambdaprev); 1714 d = b*b - 3*a*initslope; 1715 if (d < 0.0) d = 0.0; 1716 if (a == 0.0) { 1717 lambdatemp = -initslope/(2.0*b); 1718 } else { 1719 lambdatemp = (-b + sqrt(d))/(3.0*a); 1720 } 1721 lambdaprev = lambda; 1722 gnormprev = *gnorm; 1723 if (lambdatemp > .5*lambda) lambdatemp = .5*lambda; 1724 if (lambdatemp <= .1*lambda) lambda = .1*lambda; 1725 else lambda = lambdatemp; 1726 ierr = VecWAXPY(w,-lambda,y,x);CHKERRQ(ierr); 1727 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1728 if (snes->nfuncs >= snes->max_funcs) { 1729 ierr = PetscInfo1(snes,"Exceeded maximum function evaluations, while looking for good step length! %D \n",count);CHKERRQ(ierr); 1730 ierr = PetscInfo5(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lambda=%18.16e, initial slope=%18.16e\n",fnorm,*gnorm,*ynorm,lambda,initslope);CHKERRQ(ierr); 1731 *flag = PETSC_FALSE; 1732 snes->reason = SNES_DIVERGED_FUNCTION_COUNT; 1733 break; 1734 } 1735 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1736 if (snes->ops->solve != SNESSolveVI_SS) { 1737 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1738 } else { 1739 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1740 } 1741 if (snes->domainerror) { 1742 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1743 PetscFunctionReturn(0); 1744 } 1745 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1746 if (.5*(*gnorm)*(*gnorm) < .5*fnorm*fnorm + lambda*vi->alpha*initslope) { /* is reduction enough? */ 1747 if (vi->lsmonitor) { 1748 ierr = PetscPrintf(comm," Line search: Cubically determined step, current gnorm %G lambda=%18.16e\n",*gnorm,lambda);CHKERRQ(ierr); 1749 } 1750 break; 1751 } else { 1752 if (vi->lsmonitor) { 1753 ierr = PetscPrintf(comm," Line search: Cubic step no good, shrinking lambda, current gnorm %G lambda=%18.16e\n",*gnorm,lambda);CHKERRQ(ierr); 1754 } 1755 } 1756 count++; 1757 } 1758 theend1: 1759 /* Optional user-defined check for line search step validity */ 1760 if (vi->postcheckstep && *flag) { 1761 ierr = (*vi->postcheckstep)(snes,x,y,w,vi->postcheck,&changed_y,&changed_w);CHKERRQ(ierr); 1762 if (changed_y) { 1763 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); 1764 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1765 } 1766 if (changed_y || changed_w) { /* recompute the function if the step has changed */ 1767 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1768 if (snes->ops->solve != SNESSolveVI_SS) { 1769 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1770 } else { 1771 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1772 } 1773 if (snes->domainerror) { 1774 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1775 PetscFunctionReturn(0); 1776 } 1777 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1778 ierr = VecNormBegin(y,NORM_2,ynorm);CHKERRQ(ierr); 1779 ierr = VecNormEnd(y,NORM_2,ynorm);CHKERRQ(ierr); 1780 } 1781 } 1782 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1783 PetscFunctionReturn(0); 1784 } 1785 1786 #undef __FUNCT__ 1787 #define __FUNCT__ "SNESLineSearchQuadratic_VI" 1788 /* 1789 This routine does a quadratic line search while keeping the iterates within the variable bounds 1790 */ 1791 PetscErrorCode SNESLineSearchQuadratic_VI(SNES snes,void *lsctx,Vec x,Vec f,Vec g,Vec y,Vec w,PetscReal fnorm,PetscReal xnorm,PetscReal *ynorm,PetscReal *gnorm,PetscBool *flag) 1792 { 1793 /* 1794 Note that for line search purposes we work with with the related 1795 minimization problem: 1796 min z(x): R^n -> R, 1797 where z(x) = .5 * fnorm*fnorm,and fnorm = || f ||_2. 1798 */ 1799 PetscReal initslope,minlambda,lambda,lambdatemp,rellength; 1800 #if defined(PETSC_USE_COMPLEX) 1801 PetscScalar cinitslope; 1802 #endif 1803 PetscErrorCode ierr; 1804 PetscInt count; 1805 SNES_VI *vi = (SNES_VI*)snes->data; 1806 PetscBool changed_w = PETSC_FALSE,changed_y = PETSC_FALSE; 1807 1808 PetscFunctionBegin; 1809 ierr = PetscLogEventBegin(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1810 *flag = PETSC_TRUE; 1811 1812 ierr = VecNorm(y,NORM_2,ynorm);CHKERRQ(ierr); 1813 if (*ynorm == 0.0) { 1814 if (vi->lsmonitor) { 1815 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor,"Line search: Direction and size is 0\n");CHKERRQ(ierr); 1816 } 1817 *gnorm = fnorm; 1818 ierr = VecCopy(x,w);CHKERRQ(ierr); 1819 ierr = VecCopy(f,g);CHKERRQ(ierr); 1820 *flag = PETSC_FALSE; 1821 goto theend2; 1822 } 1823 if (*ynorm > vi->maxstep) { /* Step too big, so scale back */ 1824 ierr = VecScale(y,vi->maxstep/(*ynorm));CHKERRQ(ierr); 1825 *ynorm = vi->maxstep; 1826 } 1827 ierr = VecMaxPointwiseDivide(y,x,&rellength);CHKERRQ(ierr); 1828 minlambda = vi->minlambda/rellength; 1829 ierr = MatMult(snes->jacobian,y,w);CHKERRQ(ierr); 1830 #if defined(PETSC_USE_COMPLEX) 1831 ierr = VecDot(f,w,&cinitslope);CHKERRQ(ierr); 1832 initslope = PetscRealPart(cinitslope); 1833 #else 1834 ierr = VecDot(f,w,&initslope);CHKERRQ(ierr); 1835 #endif 1836 if (initslope > 0.0) initslope = -initslope; 1837 if (initslope == 0.0) initslope = -1.0; 1838 ierr = PetscInfo1(snes,"Initslope %G \n",initslope);CHKERRQ(ierr); 1839 1840 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); 1841 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1842 if (snes->nfuncs >= snes->max_funcs) { 1843 ierr = PetscInfo(snes,"Exceeded maximum function evaluations, while checking full step length!\n");CHKERRQ(ierr); 1844 *flag = PETSC_FALSE; 1845 snes->reason = SNES_DIVERGED_FUNCTION_COUNT; 1846 goto theend2; 1847 } 1848 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1849 if (snes->ops->solve != SNESSolveVI_SS) { 1850 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1851 } else { 1852 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1853 } 1854 if (snes->domainerror) { 1855 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1856 PetscFunctionReturn(0); 1857 } 1858 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1859 if (.5*(*gnorm)*(*gnorm) <= .5*fnorm*fnorm + vi->alpha*initslope) { /* Sufficient reduction */ 1860 if (vi->lsmonitor) { 1861 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Using full step: fnorm %G gnorm %G\n",fnorm,*gnorm);CHKERRQ(ierr); 1862 } 1863 goto theend2; 1864 } 1865 1866 /* Fit points with quadratic */ 1867 lambda = 1.0; 1868 count = 1; 1869 while (PETSC_TRUE) { 1870 if (lambda <= minlambda) { /* bad luck; use full step */ 1871 if (vi->lsmonitor) { 1872 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor,"Line search: Unable to find good step length! %D \n",count);CHKERRQ(ierr); 1873 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor,"Line search: fnorm=%G, gnorm=%G, ynorm=%G, lambda=%G, initial slope=%G\n",fnorm,*gnorm,*ynorm,lambda,initslope);CHKERRQ(ierr); 1874 } 1875 ierr = VecCopy(x,w);CHKERRQ(ierr); 1876 *flag = PETSC_FALSE; 1877 break; 1878 } 1879 lambdatemp = -initslope/((*gnorm)*(*gnorm) - fnorm*fnorm - 2.0*initslope); 1880 if (lambdatemp > .5*lambda) lambdatemp = .5*lambda; 1881 if (lambdatemp <= .1*lambda) lambda = .1*lambda; 1882 else lambda = lambdatemp; 1883 1884 ierr = VecWAXPY(w,-lambda,y,x);CHKERRQ(ierr); 1885 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1886 if (snes->nfuncs >= snes->max_funcs) { 1887 ierr = PetscInfo1(snes,"Exceeded maximum function evaluations, while looking for good step length! %D \n",count);CHKERRQ(ierr); 1888 ierr = PetscInfo5(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lambda=%18.16e, initial slope=%18.16e\n",fnorm,*gnorm,*ynorm,lambda,initslope);CHKERRQ(ierr); 1889 *flag = PETSC_FALSE; 1890 snes->reason = SNES_DIVERGED_FUNCTION_COUNT; 1891 break; 1892 } 1893 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1894 if (snes->domainerror) { 1895 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1896 PetscFunctionReturn(0); 1897 } 1898 if (snes->ops->solve != SNESSolveVI_SS) { 1899 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1900 } else { 1901 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1902 } 1903 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1904 if (.5*(*gnorm)*(*gnorm) < .5*fnorm*fnorm + lambda*vi->alpha*initslope) { /* sufficient reduction */ 1905 if (vi->lsmonitor) { 1906 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line Search: Quadratically determined step, lambda=%G\n",lambda);CHKERRQ(ierr); 1907 } 1908 break; 1909 } 1910 count++; 1911 } 1912 theend2: 1913 /* Optional user-defined check for line search step validity */ 1914 if (vi->postcheckstep) { 1915 ierr = (*vi->postcheckstep)(snes,x,y,w,vi->postcheck,&changed_y,&changed_w);CHKERRQ(ierr); 1916 if (changed_y) { 1917 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); 1918 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1919 } 1920 if (changed_y || changed_w) { /* recompute the function if the step has changed */ 1921 ierr = SNESComputeFunction(snes,w,g); 1922 if (snes->domainerror) { 1923 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1924 PetscFunctionReturn(0); 1925 } 1926 if (snes->ops->solve != SNESSolveVI_SS) { 1927 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1928 } else { 1929 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1930 } 1931 1932 ierr = VecNormBegin(y,NORM_2,ynorm);CHKERRQ(ierr); 1933 ierr = VecNormEnd(y,NORM_2,ynorm);CHKERRQ(ierr); 1934 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1935 } 1936 } 1937 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1938 PetscFunctionReturn(0); 1939 } 1940 1941 typedef PetscErrorCode (*FCN2)(SNES,void*,Vec,Vec,Vec,Vec,Vec,PetscReal,PetscReal,PetscReal*,PetscReal*,PetscBool*); /* force argument to next function to not be extern C*/ 1942 /* -------------------------------------------------------------------------- */ 1943 EXTERN_C_BEGIN 1944 #undef __FUNCT__ 1945 #define __FUNCT__ "SNESLineSearchSet_VI" 1946 PetscErrorCode SNESLineSearchSet_VI(SNES snes,FCN2 func,void *lsctx) 1947 { 1948 PetscFunctionBegin; 1949 ((SNES_VI *)(snes->data))->LineSearch = func; 1950 ((SNES_VI *)(snes->data))->lsP = lsctx; 1951 PetscFunctionReturn(0); 1952 } 1953 EXTERN_C_END 1954 1955 /* -------------------------------------------------------------------------- */ 1956 EXTERN_C_BEGIN 1957 #undef __FUNCT__ 1958 #define __FUNCT__ "SNESLineSearchSetMonitor_VI" 1959 PetscErrorCode SNESLineSearchSetMonitor_VI(SNES snes,PetscBool flg) 1960 { 1961 SNES_VI *vi = (SNES_VI*)snes->data; 1962 PetscErrorCode ierr; 1963 1964 PetscFunctionBegin; 1965 if (flg && !vi->lsmonitor) { 1966 ierr = PetscViewerASCIIMonitorCreate(((PetscObject)snes)->comm,"stdout",((PetscObject)snes)->tablevel,&vi->lsmonitor);CHKERRQ(ierr); 1967 } else if (!flg && vi->lsmonitor) { 1968 ierr = PetscViewerASCIIMonitorDestroy(vi->lsmonitor);CHKERRQ(ierr); 1969 } 1970 PetscFunctionReturn(0); 1971 } 1972 EXTERN_C_END 1973 1974 /* 1975 SNESView_VI - Prints info from the SNESVI data structure. 1976 1977 Input Parameters: 1978 . SNES - the SNES context 1979 . viewer - visualization context 1980 1981 Application Interface Routine: SNESView() 1982 */ 1983 #undef __FUNCT__ 1984 #define __FUNCT__ "SNESView_VI" 1985 static PetscErrorCode SNESView_VI(SNES snes,PetscViewer viewer) 1986 { 1987 SNES_VI *vi = (SNES_VI *)snes->data; 1988 const char *cstr,*tstr; 1989 PetscErrorCode ierr; 1990 PetscBool iascii; 1991 1992 PetscFunctionBegin; 1993 ierr = PetscTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr); 1994 if (iascii) { 1995 if (vi->LineSearch == SNESLineSearchNo_VI) cstr = "SNESLineSearchNo"; 1996 else if (vi->LineSearch == SNESLineSearchQuadratic_VI) cstr = "SNESLineSearchQuadratic"; 1997 else if (vi->LineSearch == SNESLineSearchCubic_VI) cstr = "SNESLineSearchCubic"; 1998 else cstr = "unknown"; 1999 if (snes->ops->solve == SNESSolveVI_SS) tstr = "Semismooth"; 2000 else if (snes->ops->solve == SNESSolveVI_RS) tstr = "Reduced Space"; 2001 else if (snes->ops->solve == SNESSolveVI_RS2) tstr = "Augmented Space"; 2002 else tstr = "unknown"; 2003 ierr = PetscViewerASCIIPrintf(viewer," VI algorithm: %s\n",tstr);CHKERRQ(ierr); 2004 ierr = PetscViewerASCIIPrintf(viewer," line search variant: %s\n",cstr);CHKERRQ(ierr); 2005 ierr = PetscViewerASCIIPrintf(viewer," alpha=%G, maxstep=%G, minlambda=%G\n",vi->alpha,vi->maxstep,vi->minlambda);CHKERRQ(ierr); 2006 } else { 2007 SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Viewer type %s not supported for SNES EQ VI",((PetscObject)viewer)->type_name); 2008 } 2009 PetscFunctionReturn(0); 2010 } 2011 2012 #undef __FUNCT__ 2013 #define __FUNCT__ "SNESVISetVariableBounds" 2014 /*@ 2015 SNESVISetVariableBounds - Sets the lower and upper bounds for the solution vector. xl <= x <= xu. 2016 2017 Input Parameters: 2018 . snes - the SNES context. 2019 . xl - lower bound. 2020 . xu - upper bound. 2021 2022 Notes: 2023 If this routine is not called then the lower and upper bounds are set to 2024 PETSC_VI_INF and PETSC_VI_NINF respectively during SNESSetUp(). 2025 2026 @*/ 2027 PetscErrorCode SNESVISetVariableBounds(SNES snes, Vec xl, Vec xu) 2028 { 2029 SNES_VI *vi = (SNES_VI*)snes->data; 2030 2031 PetscFunctionBegin; 2032 PetscValidHeaderSpecific(snes,SNES_CLASSID,1); 2033 PetscValidHeaderSpecific(xl,VEC_CLASSID,2); 2034 PetscValidHeaderSpecific(xu,VEC_CLASSID,3); 2035 if (!snes->vec_func) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Must call SNESSetFunction() first"); 2036 if (xl->map->N != snes->vec_func->map->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Incompatible vector lengths lower bound = %D solution vector = %D",xl->map->N,snes->vec_func->map->N); 2037 if (xu->map->N != snes->vec_func->map->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Incompatible vector lengths: upper bound = %D solution vector = %D",xu->map->N,snes->vec_func->map->N); 2038 2039 vi->usersetxbounds = PETSC_TRUE; 2040 vi->xl = xl; 2041 vi->xu = xu; 2042 PetscFunctionReturn(0); 2043 } 2044 2045 /* -------------------------------------------------------------------------- */ 2046 /* 2047 SNESSetFromOptions_VI - Sets various parameters for the SNESVI method. 2048 2049 Input Parameter: 2050 . snes - the SNES context 2051 2052 Application Interface Routine: SNESSetFromOptions() 2053 */ 2054 #undef __FUNCT__ 2055 #define __FUNCT__ "SNESSetFromOptions_VI" 2056 static PetscErrorCode SNESSetFromOptions_VI(SNES snes) 2057 { 2058 SNES_VI *vi = (SNES_VI *)snes->data; 2059 const char *lses[] = {"basic","basicnonorms","quadratic","cubic"}; 2060 const char *vies[] = {"ss","rs","rs2"}; 2061 PetscErrorCode ierr; 2062 PetscInt indx; 2063 PetscBool flg,set,flg2; 2064 2065 PetscFunctionBegin; 2066 ierr = PetscOptionsHead("SNES semismooth method options");CHKERRQ(ierr); 2067 ierr = PetscOptionsBool("-snes_vi_monitor","Monitor all non-active variables","None",PETSC_FALSE,&flg,0);CHKERRQ(ierr); 2068 if (flg) { 2069 ierr = SNESMonitorSet(snes,SNESMonitorVI,0,0);CHKERRQ(ierr); 2070 } 2071 ierr = PetscOptionsReal("-snes_ls_alpha","Function norm must decrease by","None",vi->alpha,&vi->alpha,0);CHKERRQ(ierr); 2072 ierr = PetscOptionsReal("-snes_ls_maxstep","Step must be less than","None",vi->maxstep,&vi->maxstep,0);CHKERRQ(ierr); 2073 ierr = PetscOptionsReal("-snes_ls_minlambda","Minimum lambda allowed","None",vi->minlambda,&vi->minlambda,0);CHKERRQ(ierr); 2074 ierr = PetscOptionsReal("-snes_vi_const_tol","constraint tolerance","None",vi->const_tol,&vi->const_tol,0);CHKERRQ(ierr); 2075 ierr = PetscOptionsBool("-snes_ls_monitor","Print progress of line searches","SNESLineSearchSetMonitor",vi->lsmonitor ? PETSC_TRUE : PETSC_FALSE,&flg,&set);CHKERRQ(ierr); 2076 if (set) {ierr = SNESLineSearchSetMonitor(snes,flg);CHKERRQ(ierr);} 2077 ierr = PetscOptionsEList("-snes_vi_type","Semismooth algorithm used","",vies,3,"ss",&indx,&flg2);CHKERRQ(ierr); 2078 if (flg2) { 2079 switch (indx) { 2080 case 0: 2081 snes->ops->solve = SNESSolveVI_SS; 2082 break; 2083 case 1: 2084 snes->ops->solve = SNESSolveVI_RS; 2085 break; 2086 case 2: 2087 snes->ops->solve = SNESSolveVI_RS2; 2088 } 2089 } 2090 ierr = PetscOptionsEList("-snes_ls","Line search used","SNESLineSearchSet",lses,4,"basic",&indx,&flg);CHKERRQ(ierr); 2091 if (flg) { 2092 switch (indx) { 2093 case 0: 2094 ierr = SNESLineSearchSet(snes,SNESLineSearchNo_VI,PETSC_NULL);CHKERRQ(ierr); 2095 break; 2096 case 1: 2097 ierr = SNESLineSearchSet(snes,SNESLineSearchNoNorms_VI,PETSC_NULL);CHKERRQ(ierr); 2098 break; 2099 case 2: 2100 ierr = SNESLineSearchSet(snes,SNESLineSearchQuadratic_VI,PETSC_NULL);CHKERRQ(ierr); 2101 break; 2102 case 3: 2103 ierr = SNESLineSearchSet(snes,SNESLineSearchCubic_VI,PETSC_NULL);CHKERRQ(ierr); 2104 break; 2105 } 2106 } 2107 ierr = PetscOptionsTail();CHKERRQ(ierr); 2108 PetscFunctionReturn(0); 2109 } 2110 /* -------------------------------------------------------------------------- */ 2111 /*MC 2112 SNESVI - Semismooth newton method based nonlinear solver that uses a line search 2113 2114 Options Database: 2115 + -snes_ls [cubic,quadratic,basic,basicnonorms] - Selects line search 2116 . -snes_ls_alpha <alpha> - Sets alpha 2117 . -snes_ls_maxstep <maxstep> - Sets the maximum stepsize the line search will use (if the 2-norm(y) > maxstep then scale y to be y = (maxstep/2-norm(y)) *y) 2118 . -snes_ls_minlambda <minlambda> - Sets the minimum lambda the line search will use minlambda / max_i ( y[i]/x[i] ) 2119 - -snes_ls_monitor - print information about progress of line searches 2120 2121 2122 Level: beginner 2123 2124 .seealso: SNESCreate(), SNES, SNESSetType(), SNESTR, SNESLineSearchSet(), 2125 SNESLineSearchSetPostCheck(), SNESLineSearchNo(), SNESLineSearchCubic(), SNESLineSearchQuadratic(), 2126 SNESLineSearchSet(), SNESLineSearchNoNorms(), SNESLineSearchSetPreCheck(), SNESLineSearchSetParams(), SNESLineSearchGetParams() 2127 2128 M*/ 2129 EXTERN_C_BEGIN 2130 #undef __FUNCT__ 2131 #define __FUNCT__ "SNESCreate_VI" 2132 PetscErrorCode SNESCreate_VI(SNES snes) 2133 { 2134 PetscErrorCode ierr; 2135 SNES_VI *vi; 2136 2137 PetscFunctionBegin; 2138 snes->ops->setup = SNESSetUp_VI; 2139 snes->ops->solve = SNESSolveVI_SS; 2140 snes->ops->destroy = SNESDestroy_VI; 2141 snes->ops->setfromoptions = SNESSetFromOptions_VI; 2142 snes->ops->view = SNESView_VI; 2143 snes->ops->reset = 0; /* XXX Implement!!! */ 2144 snes->ops->converged = SNESDefaultConverged_VI; 2145 2146 ierr = PetscNewLog(snes,SNES_VI,&vi);CHKERRQ(ierr); 2147 snes->data = (void*)vi; 2148 vi->alpha = 1.e-4; 2149 vi->maxstep = 1.e8; 2150 vi->minlambda = 1.e-12; 2151 vi->LineSearch = SNESLineSearchNo_VI; 2152 vi->lsP = PETSC_NULL; 2153 vi->postcheckstep = PETSC_NULL; 2154 vi->postcheck = PETSC_NULL; 2155 vi->precheckstep = PETSC_NULL; 2156 vi->precheck = PETSC_NULL; 2157 vi->const_tol = 2.2204460492503131e-16; 2158 vi->checkredundancy = PETSC_NULL; 2159 2160 ierr = PetscObjectComposeFunctionDynamic((PetscObject)snes,"SNESLineSearchSetMonitor_C","SNESLineSearchSetMonitor_VI",SNESLineSearchSetMonitor_VI);CHKERRQ(ierr); 2161 ierr = PetscObjectComposeFunctionDynamic((PetscObject)snes,"SNESLineSearchSet_C","SNESLineSearchSet_VI",SNESLineSearchSet_VI);CHKERRQ(ierr); 2162 2163 PetscFunctionReturn(0); 2164 } 2165 EXTERN_C_END 2166