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 /* Preallocate augmented matrix and set values in it...Doing only sequential case first*/ 1212 PetscInt ncols; 1213 const PetscInt *cols; 1214 const PetscScalar *vals; 1215 PetscScalar value=1.0; 1216 PetscInt row,col; 1217 PetscInt *d_nnz; 1218 1219 ierr = PetscMalloc((X->map->n+nkept)*sizeof(PetscInt),&d_nnz);CHKERRQ(ierr); 1220 ierr = PetscMemzero(d_nnz,(X->map->n+nkept)*sizeof(PetscInt));CHKERRQ(ierr); 1221 for(row=0;row<snes->jacobian->rmap->n;row++) { 1222 ierr = MatGetRow(snes->jacobian,row,&ncols,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr); 1223 d_nnz[row] += ncols; 1224 ierr = MatRestoreRow(snes->jacobian,row,&ncols,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr); 1225 } 1226 1227 for(k=0;k<nkept;k++) { 1228 d_nnz[idx_actkept[k]] += 1; 1229 d_nnz[snes->jacobian->rmap->n+k] += 1; 1230 } 1231 ierr = MatSeqAIJSetPreallocation(J_aug,PETSC_NULL,d_nnz);CHKERRQ(ierr); 1232 1233 ierr = PetscFree(d_nnz);CHKERRQ(ierr); 1234 1235 /* Set the original jacobian matrix in J_aug */ 1236 for(row=0;row<snes->jacobian->rmap->n;row++) { 1237 ierr = MatGetRow(snes->jacobian,row,&ncols,&cols,&vals);CHKERRQ(ierr); 1238 ierr = MatSetValues(J_aug,1,&row,ncols,cols,vals,INSERT_VALUES);CHKERRQ(ierr); 1239 ierr = MatRestoreRow(snes->jacobian,row,&ncols,&cols,&vals);CHKERRQ(ierr); 1240 } 1241 /* Add the augmented part */ 1242 for(k=0;k<nkept;k++) { 1243 row = idx_actkept[k]; 1244 col = snes->jacobian->rmap->n+k; 1245 ierr = MatSetValues(J_aug,1,&row,1,&col,&value,INSERT_VALUES);CHKERRQ(ierr); 1246 ierr = MatSetValues(J_aug,1,&col,1,&row,&value,INSERT_VALUES);CHKERRQ(ierr); 1247 } 1248 ierr = MatAssemblyBegin(J_aug,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 1249 ierr = MatAssemblyEnd(J_aug,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 1250 /* Only considering prejac = jac for now */ 1251 Jpre_aug = J_aug; 1252 1253 } else { 1254 F_aug = F; J_aug = snes->jacobian; Y_aug = Y; Jpre_aug = snes->jacobian_pre; 1255 } 1256 1257 ierr = ISEqual(vi->IS_inact_prev,IS_inact,&isequal);CHKERRQ(ierr); 1258 if (!isequal) { 1259 ierr = SNESVIResetPCandKSP(snes,J_aug,Jpre_aug);CHKERRQ(ierr); 1260 } 1261 ierr = KSPSetOperators(snes->ksp,J_aug,Jpre_aug,flg);CHKERRQ(ierr); 1262 ierr = KSPSetUp(snes->ksp);CHKERRQ(ierr); 1263 /* { 1264 PC pc; 1265 PetscBool flg; 1266 ierr = KSPGetPC(snes->ksp,&pc);CHKERRQ(ierr); 1267 ierr = PetscTypeCompare((PetscObject)pc,PCFIELDSPLIT,&flg);CHKERRQ(ierr); 1268 if (flg) { 1269 KSP *subksps; 1270 ierr = PCFieldSplitGetSubKSP(pc,PETSC_NULL,&subksps);CHKERRQ(ierr); 1271 ierr = KSPGetPC(subksps[0],&pc);CHKERRQ(ierr); 1272 ierr = PetscFree(subksps);CHKERRQ(ierr); 1273 ierr = PetscTypeCompare((PetscObject)pc,PCBJACOBI,&flg);CHKERRQ(ierr); 1274 if (flg) { 1275 PetscInt n,N = 101*101,j,cnts[3] = {0,0,0}; 1276 const PetscInt *ii; 1277 1278 ierr = ISGetSize(IS_inact,&n);CHKERRQ(ierr); 1279 ierr = ISGetIndices(IS_inact,&ii);CHKERRQ(ierr); 1280 for (j=0; j<n; j++) { 1281 if (ii[j] < N) cnts[0]++; 1282 else if (ii[j] < 2*N) cnts[1]++; 1283 else if (ii[j] < 3*N) cnts[2]++; 1284 } 1285 ierr = ISRestoreIndices(IS_inact,&ii);CHKERRQ(ierr); 1286 1287 ierr = PCBJacobiSetTotalBlocks(pc,3,cnts);CHKERRQ(ierr); 1288 } 1289 } 1290 } 1291 */ 1292 ierr = SNES_KSPSolve(snes,snes->ksp,F_aug,Y_aug);CHKERRQ(ierr); 1293 ierr = KSPGetConvergedReason(snes->ksp,&kspreason);CHKERRQ(ierr); 1294 if (kspreason < 0) { 1295 if (++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) { 1296 ierr = PetscInfo2(snes,"iter=%D, number linear solve failures %D greater than current SNES allowed, stopping solve\n",snes->iter,snes->numLinearSolveFailures);CHKERRQ(ierr); 1297 snes->reason = SNES_DIVERGED_LINEAR_SOLVE; 1298 break; 1299 } 1300 } 1301 1302 if(nis_act) { 1303 PetscScalar *y1,*y2; 1304 ierr = VecGetArray(Y,&y1);CHKERRQ(ierr); 1305 ierr = VecGetArray(Y_aug,&y2);CHKERRQ(ierr); 1306 /* Copy over inactive Y_aug to Y */ 1307 j1 = 0; 1308 for(i1=Y->map->rstart;i1 < Y->map->rend;i1++) { 1309 if(j1 < nkept && idx_actkept[j1] == i1) j1++; 1310 else y1[i1-Y->map->rstart] = y2[i1-Y->map->rstart]; 1311 } 1312 ierr = VecRestoreArray(Y,&y1);CHKERRQ(ierr); 1313 ierr = VecRestoreArray(Y_aug,&y2);CHKERRQ(ierr); 1314 1315 ierr = VecDestroy(F_aug);CHKERRQ(ierr); 1316 ierr = VecDestroy(Y_aug);CHKERRQ(ierr); 1317 ierr = MatDestroy(J_aug);CHKERRQ(ierr); 1318 ierr = PetscFree(idx_actkept);CHKERRQ(ierr); 1319 } 1320 1321 if (!isequal) { 1322 ierr = ISDestroy(vi->IS_inact_prev);CHKERRQ(ierr); 1323 ierr = ISDuplicate(IS_inact,&vi->IS_inact_prev);CHKERRQ(ierr); 1324 } 1325 ierr = ISDestroy(IS_inact);CHKERRQ(ierr); 1326 1327 ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr); 1328 snes->linear_its += lits; 1329 ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr); 1330 /* 1331 if (vi->precheckstep) { 1332 PetscBool changed_y = PETSC_FALSE; 1333 ierr = (*vi->precheckstep)(snes,X,Y,vi->precheck,&changed_y);CHKERRQ(ierr); 1334 } 1335 1336 if (PetscLogPrintInfo){ 1337 ierr = SNESVICheckResidual_Private(snes,snes->jacobian,F,Y,G,W);CHKERRQ(ierr); 1338 } 1339 */ 1340 /* Compute a (scaled) negative update in the line search routine: 1341 Y <- X - lambda*Y 1342 and evaluate G = function(Y) (depends on the line search). 1343 */ 1344 ierr = VecCopy(Y,snes->vec_sol_update);CHKERRQ(ierr); 1345 ynorm = 1; gnorm = fnorm; 1346 ierr = (*vi->LineSearch)(snes,vi->lsP,X,F,G,Y,W,fnorm,xnorm,&ynorm,&gnorm,&lssucceed);CHKERRQ(ierr); 1347 ierr = PetscInfo4(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lssucceed=%d\n",fnorm,gnorm,ynorm,(int)lssucceed);CHKERRQ(ierr); 1348 if (snes->reason == SNES_DIVERGED_FUNCTION_COUNT) break; 1349 if (snes->domainerror) { 1350 snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; 1351 PetscFunctionReturn(0); 1352 } 1353 if (!lssucceed) { 1354 if (++snes->numFailures >= snes->maxFailures) { 1355 PetscBool ismin; 1356 snes->reason = SNES_DIVERGED_LINE_SEARCH; 1357 ierr = SNESVICheckLocalMin_Private(snes,snes->jacobian,G,W,gnorm,&ismin);CHKERRQ(ierr); 1358 if (ismin) snes->reason = SNES_DIVERGED_LOCAL_MIN; 1359 break; 1360 } 1361 } 1362 /* Update function and solution vectors */ 1363 fnorm = gnorm; 1364 ierr = VecCopy(G,F);CHKERRQ(ierr); 1365 ierr = VecCopy(W,X);CHKERRQ(ierr); 1366 /* Monitor convergence */ 1367 ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); 1368 snes->iter = i+1; 1369 snes->norm = fnorm; 1370 ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); 1371 SNESLogConvHistory(snes,snes->norm,lits); 1372 SNESMonitor(snes,snes->iter,snes->norm); 1373 /* Test for convergence, xnorm = || X || */ 1374 if (snes->ops->converged != SNESSkipConverged) { ierr = VecNorm(X,NORM_2,&xnorm);CHKERRQ(ierr); } 1375 ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); 1376 if (snes->reason) break; 1377 } 1378 if (i == maxits) { 1379 ierr = PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",maxits);CHKERRQ(ierr); 1380 if(!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT; 1381 } 1382 PetscFunctionReturn(0); 1383 } 1384 1385 /* -------------------------------------------------------------------------- */ 1386 /* 1387 SNESSetUp_VI - Sets up the internal data structures for the later use 1388 of the SNESVI nonlinear solver. 1389 1390 Input Parameter: 1391 . snes - the SNES context 1392 . x - the solution vector 1393 1394 Application Interface Routine: SNESSetUp() 1395 1396 Notes: 1397 For basic use of the SNES solvers, the user need not explicitly call 1398 SNESSetUp(), since these actions will automatically occur during 1399 the call to SNESSolve(). 1400 */ 1401 #undef __FUNCT__ 1402 #define __FUNCT__ "SNESSetUp_VI" 1403 PetscErrorCode SNESSetUp_VI(SNES snes) 1404 { 1405 PetscErrorCode ierr; 1406 SNES_VI *vi = (SNES_VI*) snes->data; 1407 PetscInt i_start[3],i_end[3]; 1408 1409 PetscFunctionBegin; 1410 if (!snes->vec_sol_update) { 1411 ierr = VecDuplicate(snes->vec_sol,&snes->vec_sol_update);CHKERRQ(ierr); 1412 ierr = PetscLogObjectParent(snes,snes->vec_sol_update);CHKERRQ(ierr); 1413 } 1414 if (!snes->work) { 1415 snes->nwork = 3; 1416 ierr = VecDuplicateVecs(snes->vec_sol,snes->nwork,&snes->work);CHKERRQ(ierr); 1417 ierr = PetscLogObjectParents(snes,snes->nwork,snes->work);CHKERRQ(ierr); 1418 } 1419 1420 /* If the lower and upper bound on variables are not set, set it to 1421 -Inf and Inf */ 1422 if (!vi->xl && !vi->xu) { 1423 vi->usersetxbounds = PETSC_FALSE; 1424 ierr = VecDuplicate(snes->vec_sol, &vi->xl); CHKERRQ(ierr); 1425 ierr = VecSet(vi->xl,PETSC_VI_NINF);CHKERRQ(ierr); 1426 ierr = VecDuplicate(snes->vec_sol, &vi->xu); CHKERRQ(ierr); 1427 ierr = VecSet(vi->xu,PETSC_VI_INF);CHKERRQ(ierr); 1428 } else { 1429 /* Check if lower bound, upper bound and solution vector distribution across the processors is identical */ 1430 ierr = VecGetOwnershipRange(snes->vec_sol,i_start,i_end);CHKERRQ(ierr); 1431 ierr = VecGetOwnershipRange(vi->xl,i_start+1,i_end+1);CHKERRQ(ierr); 1432 ierr = VecGetOwnershipRange(vi->xu,i_start+2,i_end+2);CHKERRQ(ierr); 1433 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])) 1434 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."); 1435 } 1436 if (snes->ops->solve != SNESSolveVI_SS) { 1437 /* Set up previous active index set for the first snes solve 1438 vi->IS_inact_prev = 0,1,2,....N */ 1439 PetscInt *indices; 1440 PetscInt i,n,rstart,rend; 1441 1442 ierr = VecGetOwnershipRange(snes->vec_sol,&rstart,&rend);CHKERRQ(ierr); 1443 ierr = VecGetLocalSize(snes->vec_sol,&n);CHKERRQ(ierr); 1444 ierr = PetscMalloc(n*sizeof(PetscInt),&indices);CHKERRQ(ierr); 1445 for(i=0;i < n; i++) indices[i] = rstart + i; 1446 ierr = ISCreateGeneral(((PetscObject)snes)->comm,n,indices,PETSC_OWN_POINTER,&vi->IS_inact_prev); 1447 } 1448 1449 if (snes->ops->solve == SNESSolveVI_SS) { 1450 ierr = VecDuplicate(snes->vec_sol, &vi->dpsi);CHKERRQ(ierr); 1451 ierr = VecDuplicate(snes->vec_sol, &vi->phi); CHKERRQ(ierr); 1452 ierr = VecDuplicate(snes->vec_sol, &vi->Da); CHKERRQ(ierr); 1453 ierr = VecDuplicate(snes->vec_sol, &vi->Db); CHKERRQ(ierr); 1454 ierr = VecDuplicate(snes->vec_sol, &vi->z);CHKERRQ(ierr); 1455 ierr = VecDuplicate(snes->vec_sol, &vi->t); CHKERRQ(ierr); 1456 } 1457 PetscFunctionReturn(0); 1458 } 1459 /* -------------------------------------------------------------------------- */ 1460 /* 1461 SNESDestroy_VI - Destroys the private SNES_VI context that was created 1462 with SNESCreate_VI(). 1463 1464 Input Parameter: 1465 . snes - the SNES context 1466 1467 Application Interface Routine: SNESDestroy() 1468 */ 1469 #undef __FUNCT__ 1470 #define __FUNCT__ "SNESDestroy_VI" 1471 PetscErrorCode SNESDestroy_VI(SNES snes) 1472 { 1473 SNES_VI *vi = (SNES_VI*) snes->data; 1474 PetscErrorCode ierr; 1475 1476 PetscFunctionBegin; 1477 if (snes->vec_sol_update) { 1478 ierr = VecDestroy(snes->vec_sol_update);CHKERRQ(ierr); 1479 snes->vec_sol_update = PETSC_NULL; 1480 } 1481 if (snes->work) { 1482 ierr = VecDestroyVecs(snes->nwork,&snes->work);CHKERRQ(ierr); 1483 } 1484 if (snes->ops->solve != SNESSolveVI_SS) { 1485 ierr = ISDestroy(vi->IS_inact_prev); 1486 } 1487 1488 if (snes->ops->solve == SNESSolveVI_SS) { 1489 /* clear vectors */ 1490 ierr = VecDestroy(vi->dpsi);CHKERRQ(ierr); 1491 ierr = VecDestroy(vi->phi); CHKERRQ(ierr); 1492 ierr = VecDestroy(vi->Da); CHKERRQ(ierr); 1493 ierr = VecDestroy(vi->Db); CHKERRQ(ierr); 1494 ierr = VecDestroy(vi->z); CHKERRQ(ierr); 1495 ierr = VecDestroy(vi->t); CHKERRQ(ierr); 1496 } 1497 1498 if (!vi->usersetxbounds) { 1499 ierr = VecDestroy(vi->xl); CHKERRQ(ierr); 1500 ierr = VecDestroy(vi->xu); CHKERRQ(ierr); 1501 } 1502 1503 if (vi->lsmonitor) { 1504 ierr = PetscViewerASCIIMonitorDestroy(vi->lsmonitor);CHKERRQ(ierr); 1505 } 1506 ierr = PetscFree(snes->data);CHKERRQ(ierr); 1507 1508 /* clear composed functions */ 1509 ierr = PetscObjectComposeFunctionDynamic((PetscObject)snes,"SNESLineSearchSet_C","",PETSC_NULL);CHKERRQ(ierr); 1510 ierr = PetscObjectComposeFunctionDynamic((PetscObject)snes,"SNESLineSearchSetMonitor_C","",PETSC_NULL);CHKERRQ(ierr); 1511 PetscFunctionReturn(0); 1512 } 1513 1514 /* -------------------------------------------------------------------------- */ 1515 #undef __FUNCT__ 1516 #define __FUNCT__ "SNESLineSearchNo_VI" 1517 1518 /* 1519 This routine does not actually do a line search but it takes a full newton 1520 step while ensuring that the new iterates remain within the constraints. 1521 1522 */ 1523 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) 1524 { 1525 PetscErrorCode ierr; 1526 SNES_VI *vi = (SNES_VI*)snes->data; 1527 PetscBool changed_w = PETSC_FALSE,changed_y = PETSC_FALSE; 1528 1529 PetscFunctionBegin; 1530 *flag = PETSC_TRUE; 1531 ierr = PetscLogEventBegin(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1532 ierr = VecNorm(y,NORM_2,ynorm);CHKERRQ(ierr); /* ynorm = || y || */ 1533 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); /* w <- x - y */ 1534 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1535 if (vi->postcheckstep) { 1536 ierr = (*vi->postcheckstep)(snes,x,y,w,vi->postcheck,&changed_y,&changed_w);CHKERRQ(ierr); 1537 } 1538 if (changed_y) { 1539 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); /* w <- x - y */ 1540 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1541 } 1542 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1543 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1544 if (!snes->domainerror) { 1545 if (snes->ops->solve != SNESSolveVI_SS) { 1546 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1547 } else { 1548 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); /* gnorm = || g || */ 1549 } 1550 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1551 } 1552 if (vi->lsmonitor) { 1553 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Using full step: fnorm %G gnorm %G\n",fnorm,*gnorm);CHKERRQ(ierr); 1554 } 1555 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1556 PetscFunctionReturn(0); 1557 } 1558 1559 /* -------------------------------------------------------------------------- */ 1560 #undef __FUNCT__ 1561 #define __FUNCT__ "SNESLineSearchNoNorms_VI" 1562 1563 /* 1564 This routine is a copy of SNESLineSearchNoNorms in snes/impls/ls/ls.c 1565 */ 1566 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) 1567 { 1568 PetscErrorCode ierr; 1569 SNES_VI *vi = (SNES_VI*)snes->data; 1570 PetscBool changed_w = PETSC_FALSE,changed_y = PETSC_FALSE; 1571 1572 PetscFunctionBegin; 1573 *flag = PETSC_TRUE; 1574 ierr = PetscLogEventBegin(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1575 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); /* w <- x - y */ 1576 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1577 if (vi->postcheckstep) { 1578 ierr = (*vi->postcheckstep)(snes,x,y,w,vi->postcheck,&changed_y,&changed_w);CHKERRQ(ierr); 1579 } 1580 if (changed_y) { 1581 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); /* w <- x - y */ 1582 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1583 } 1584 1585 /* don't evaluate function the last time through */ 1586 if (snes->iter < snes->max_its-1) { 1587 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1588 } 1589 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1590 PetscFunctionReturn(0); 1591 } 1592 1593 /* -------------------------------------------------------------------------- */ 1594 #undef __FUNCT__ 1595 #define __FUNCT__ "SNESLineSearchCubic_VI" 1596 /* 1597 This routine implements a cubic line search while doing a projection on the variable bounds 1598 */ 1599 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) 1600 { 1601 PetscReal initslope,lambdaprev,gnormprev,a,b,d,t1,t2,rellength; 1602 PetscReal minlambda,lambda,lambdatemp; 1603 #if defined(PETSC_USE_COMPLEX) 1604 PetscScalar cinitslope; 1605 #endif 1606 PetscErrorCode ierr; 1607 PetscInt count; 1608 SNES_VI *vi = (SNES_VI*)snes->data; 1609 PetscBool changed_w = PETSC_FALSE,changed_y = PETSC_FALSE; 1610 MPI_Comm comm; 1611 1612 PetscFunctionBegin; 1613 ierr = PetscObjectGetComm((PetscObject)snes,&comm);CHKERRQ(ierr); 1614 ierr = PetscLogEventBegin(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1615 *flag = PETSC_TRUE; 1616 1617 ierr = VecNorm(y,NORM_2,ynorm);CHKERRQ(ierr); 1618 if (*ynorm == 0.0) { 1619 if (vi->lsmonitor) { 1620 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Initial direction and size is 0\n");CHKERRQ(ierr); 1621 } 1622 *gnorm = fnorm; 1623 ierr = VecCopy(x,w);CHKERRQ(ierr); 1624 ierr = VecCopy(f,g);CHKERRQ(ierr); 1625 *flag = PETSC_FALSE; 1626 goto theend1; 1627 } 1628 if (*ynorm > vi->maxstep) { /* Step too big, so scale back */ 1629 if (vi->lsmonitor) { 1630 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Scaling step by %G old ynorm %G\n",vi->maxstep/(*ynorm),*ynorm);CHKERRQ(ierr); 1631 } 1632 ierr = VecScale(y,vi->maxstep/(*ynorm));CHKERRQ(ierr); 1633 *ynorm = vi->maxstep; 1634 } 1635 ierr = VecMaxPointwiseDivide(y,x,&rellength);CHKERRQ(ierr); 1636 minlambda = vi->minlambda/rellength; 1637 ierr = MatMult(snes->jacobian,y,w);CHKERRQ(ierr); 1638 #if defined(PETSC_USE_COMPLEX) 1639 ierr = VecDot(f,w,&cinitslope);CHKERRQ(ierr); 1640 initslope = PetscRealPart(cinitslope); 1641 #else 1642 ierr = VecDot(f,w,&initslope);CHKERRQ(ierr); 1643 #endif 1644 if (initslope > 0.0) initslope = -initslope; 1645 if (initslope == 0.0) initslope = -1.0; 1646 1647 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); 1648 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1649 if (snes->nfuncs >= snes->max_funcs) { 1650 ierr = PetscInfo(snes,"Exceeded maximum function evaluations, while checking full step length!\n");CHKERRQ(ierr); 1651 *flag = PETSC_FALSE; 1652 snes->reason = SNES_DIVERGED_FUNCTION_COUNT; 1653 goto theend1; 1654 } 1655 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1656 if (snes->ops->solve != SNESSolveVI_SS) { 1657 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1658 } else { 1659 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1660 } 1661 if (snes->domainerror) { 1662 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1663 PetscFunctionReturn(0); 1664 } 1665 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1666 ierr = PetscInfo2(snes,"Initial fnorm %G gnorm %G\n",fnorm,*gnorm);CHKERRQ(ierr); 1667 if (.5*(*gnorm)*(*gnorm) <= .5*fnorm*fnorm + vi->alpha*initslope) { /* Sufficient reduction */ 1668 if (vi->lsmonitor) { 1669 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Using full step: fnorm %G gnorm %G\n",fnorm,*gnorm);CHKERRQ(ierr); 1670 } 1671 goto theend1; 1672 } 1673 1674 /* Fit points with quadratic */ 1675 lambda = 1.0; 1676 lambdatemp = -initslope/((*gnorm)*(*gnorm) - fnorm*fnorm - 2.0*initslope); 1677 lambdaprev = lambda; 1678 gnormprev = *gnorm; 1679 if (lambdatemp > .5*lambda) lambdatemp = .5*lambda; 1680 if (lambdatemp <= .1*lambda) lambda = .1*lambda; 1681 else lambda = lambdatemp; 1682 1683 ierr = VecWAXPY(w,-lambda,y,x);CHKERRQ(ierr); 1684 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1685 if (snes->nfuncs >= snes->max_funcs) { 1686 ierr = PetscInfo1(snes,"Exceeded maximum function evaluations, while attempting quadratic backtracking! %D \n",snes->nfuncs);CHKERRQ(ierr); 1687 *flag = PETSC_FALSE; 1688 snes->reason = SNES_DIVERGED_FUNCTION_COUNT; 1689 goto theend1; 1690 } 1691 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1692 if (snes->ops->solve != SNESSolveVI_SS) { 1693 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1694 } else { 1695 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1696 } 1697 if (snes->domainerror) { 1698 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1699 PetscFunctionReturn(0); 1700 } 1701 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1702 if (vi->lsmonitor) { 1703 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: gnorm after quadratic fit %G\n",*gnorm);CHKERRQ(ierr); 1704 } 1705 if (.5*(*gnorm)*(*gnorm) < .5*fnorm*fnorm + lambda*vi->alpha*initslope) { /* sufficient reduction */ 1706 if (vi->lsmonitor) { 1707 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Quadratically determined step, lambda=%18.16e\n",lambda);CHKERRQ(ierr); 1708 } 1709 goto theend1; 1710 } 1711 1712 /* Fit points with cubic */ 1713 count = 1; 1714 while (PETSC_TRUE) { 1715 if (lambda <= minlambda) { 1716 if (vi->lsmonitor) { 1717 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: unable to find good step length! After %D tries \n",count);CHKERRQ(ierr); 1718 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); 1719 } 1720 *flag = PETSC_FALSE; 1721 break; 1722 } 1723 t1 = .5*((*gnorm)*(*gnorm) - fnorm*fnorm) - lambda*initslope; 1724 t2 = .5*(gnormprev*gnormprev - fnorm*fnorm) - lambdaprev*initslope; 1725 a = (t1/(lambda*lambda) - t2/(lambdaprev*lambdaprev))/(lambda-lambdaprev); 1726 b = (-lambdaprev*t1/(lambda*lambda) + lambda*t2/(lambdaprev*lambdaprev))/(lambda-lambdaprev); 1727 d = b*b - 3*a*initslope; 1728 if (d < 0.0) d = 0.0; 1729 if (a == 0.0) { 1730 lambdatemp = -initslope/(2.0*b); 1731 } else { 1732 lambdatemp = (-b + sqrt(d))/(3.0*a); 1733 } 1734 lambdaprev = lambda; 1735 gnormprev = *gnorm; 1736 if (lambdatemp > .5*lambda) lambdatemp = .5*lambda; 1737 if (lambdatemp <= .1*lambda) lambda = .1*lambda; 1738 else lambda = lambdatemp; 1739 ierr = VecWAXPY(w,-lambda,y,x);CHKERRQ(ierr); 1740 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1741 if (snes->nfuncs >= snes->max_funcs) { 1742 ierr = PetscInfo1(snes,"Exceeded maximum function evaluations, while looking for good step length! %D \n",count);CHKERRQ(ierr); 1743 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); 1744 *flag = PETSC_FALSE; 1745 snes->reason = SNES_DIVERGED_FUNCTION_COUNT; 1746 break; 1747 } 1748 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1749 if (snes->ops->solve != SNESSolveVI_SS) { 1750 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1751 } else { 1752 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1753 } 1754 if (snes->domainerror) { 1755 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1756 PetscFunctionReturn(0); 1757 } 1758 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1759 if (.5*(*gnorm)*(*gnorm) < .5*fnorm*fnorm + lambda*vi->alpha*initslope) { /* is reduction enough? */ 1760 if (vi->lsmonitor) { 1761 ierr = PetscPrintf(comm," Line search: Cubically determined step, current gnorm %G lambda=%18.16e\n",*gnorm,lambda);CHKERRQ(ierr); 1762 } 1763 break; 1764 } else { 1765 if (vi->lsmonitor) { 1766 ierr = PetscPrintf(comm," Line search: Cubic step no good, shrinking lambda, current gnorm %G lambda=%18.16e\n",*gnorm,lambda);CHKERRQ(ierr); 1767 } 1768 } 1769 count++; 1770 } 1771 theend1: 1772 /* Optional user-defined check for line search step validity */ 1773 if (vi->postcheckstep && *flag) { 1774 ierr = (*vi->postcheckstep)(snes,x,y,w,vi->postcheck,&changed_y,&changed_w);CHKERRQ(ierr); 1775 if (changed_y) { 1776 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); 1777 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1778 } 1779 if (changed_y || changed_w) { /* recompute the function if the step has changed */ 1780 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1781 if (snes->ops->solve != SNESSolveVI_SS) { 1782 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1783 } else { 1784 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1785 } 1786 if (snes->domainerror) { 1787 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1788 PetscFunctionReturn(0); 1789 } 1790 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1791 ierr = VecNormBegin(y,NORM_2,ynorm);CHKERRQ(ierr); 1792 ierr = VecNormEnd(y,NORM_2,ynorm);CHKERRQ(ierr); 1793 } 1794 } 1795 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1796 PetscFunctionReturn(0); 1797 } 1798 1799 #undef __FUNCT__ 1800 #define __FUNCT__ "SNESLineSearchQuadratic_VI" 1801 /* 1802 This routine does a quadratic line search while keeping the iterates within the variable bounds 1803 */ 1804 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) 1805 { 1806 /* 1807 Note that for line search purposes we work with with the related 1808 minimization problem: 1809 min z(x): R^n -> R, 1810 where z(x) = .5 * fnorm*fnorm,and fnorm = || f ||_2. 1811 */ 1812 PetscReal initslope,minlambda,lambda,lambdatemp,rellength; 1813 #if defined(PETSC_USE_COMPLEX) 1814 PetscScalar cinitslope; 1815 #endif 1816 PetscErrorCode ierr; 1817 PetscInt count; 1818 SNES_VI *vi = (SNES_VI*)snes->data; 1819 PetscBool changed_w = PETSC_FALSE,changed_y = PETSC_FALSE; 1820 1821 PetscFunctionBegin; 1822 ierr = PetscLogEventBegin(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1823 *flag = PETSC_TRUE; 1824 1825 ierr = VecNorm(y,NORM_2,ynorm);CHKERRQ(ierr); 1826 if (*ynorm == 0.0) { 1827 if (vi->lsmonitor) { 1828 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor,"Line search: Direction and size is 0\n");CHKERRQ(ierr); 1829 } 1830 *gnorm = fnorm; 1831 ierr = VecCopy(x,w);CHKERRQ(ierr); 1832 ierr = VecCopy(f,g);CHKERRQ(ierr); 1833 *flag = PETSC_FALSE; 1834 goto theend2; 1835 } 1836 if (*ynorm > vi->maxstep) { /* Step too big, so scale back */ 1837 ierr = VecScale(y,vi->maxstep/(*ynorm));CHKERRQ(ierr); 1838 *ynorm = vi->maxstep; 1839 } 1840 ierr = VecMaxPointwiseDivide(y,x,&rellength);CHKERRQ(ierr); 1841 minlambda = vi->minlambda/rellength; 1842 ierr = MatMult(snes->jacobian,y,w);CHKERRQ(ierr); 1843 #if defined(PETSC_USE_COMPLEX) 1844 ierr = VecDot(f,w,&cinitslope);CHKERRQ(ierr); 1845 initslope = PetscRealPart(cinitslope); 1846 #else 1847 ierr = VecDot(f,w,&initslope);CHKERRQ(ierr); 1848 #endif 1849 if (initslope > 0.0) initslope = -initslope; 1850 if (initslope == 0.0) initslope = -1.0; 1851 ierr = PetscInfo1(snes,"Initslope %G \n",initslope);CHKERRQ(ierr); 1852 1853 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); 1854 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1855 if (snes->nfuncs >= snes->max_funcs) { 1856 ierr = PetscInfo(snes,"Exceeded maximum function evaluations, while checking full step length!\n");CHKERRQ(ierr); 1857 *flag = PETSC_FALSE; 1858 snes->reason = SNES_DIVERGED_FUNCTION_COUNT; 1859 goto theend2; 1860 } 1861 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1862 if (snes->ops->solve != SNESSolveVI_SS) { 1863 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1864 } else { 1865 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1866 } 1867 if (snes->domainerror) { 1868 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1869 PetscFunctionReturn(0); 1870 } 1871 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1872 if (.5*(*gnorm)*(*gnorm) <= .5*fnorm*fnorm + vi->alpha*initslope) { /* Sufficient reduction */ 1873 if (vi->lsmonitor) { 1874 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Using full step: fnorm %G gnorm %G\n",fnorm,*gnorm);CHKERRQ(ierr); 1875 } 1876 goto theend2; 1877 } 1878 1879 /* Fit points with quadratic */ 1880 lambda = 1.0; 1881 count = 1; 1882 while (PETSC_TRUE) { 1883 if (lambda <= minlambda) { /* bad luck; use full step */ 1884 if (vi->lsmonitor) { 1885 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor,"Line search: Unable to find good step length! %D \n",count);CHKERRQ(ierr); 1886 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); 1887 } 1888 ierr = VecCopy(x,w);CHKERRQ(ierr); 1889 *flag = PETSC_FALSE; 1890 break; 1891 } 1892 lambdatemp = -initslope/((*gnorm)*(*gnorm) - fnorm*fnorm - 2.0*initslope); 1893 if (lambdatemp > .5*lambda) lambdatemp = .5*lambda; 1894 if (lambdatemp <= .1*lambda) lambda = .1*lambda; 1895 else lambda = lambdatemp; 1896 1897 ierr = VecWAXPY(w,-lambda,y,x);CHKERRQ(ierr); 1898 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1899 if (snes->nfuncs >= snes->max_funcs) { 1900 ierr = PetscInfo1(snes,"Exceeded maximum function evaluations, while looking for good step length! %D \n",count);CHKERRQ(ierr); 1901 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); 1902 *flag = PETSC_FALSE; 1903 snes->reason = SNES_DIVERGED_FUNCTION_COUNT; 1904 break; 1905 } 1906 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1907 if (snes->domainerror) { 1908 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1909 PetscFunctionReturn(0); 1910 } 1911 if (snes->ops->solve != SNESSolveVI_SS) { 1912 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1913 } else { 1914 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1915 } 1916 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1917 if (.5*(*gnorm)*(*gnorm) < .5*fnorm*fnorm + lambda*vi->alpha*initslope) { /* sufficient reduction */ 1918 if (vi->lsmonitor) { 1919 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line Search: Quadratically determined step, lambda=%G\n",lambda);CHKERRQ(ierr); 1920 } 1921 break; 1922 } 1923 count++; 1924 } 1925 theend2: 1926 /* Optional user-defined check for line search step validity */ 1927 if (vi->postcheckstep) { 1928 ierr = (*vi->postcheckstep)(snes,x,y,w,vi->postcheck,&changed_y,&changed_w);CHKERRQ(ierr); 1929 if (changed_y) { 1930 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); 1931 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1932 } 1933 if (changed_y || changed_w) { /* recompute the function if the step has changed */ 1934 ierr = SNESComputeFunction(snes,w,g); 1935 if (snes->domainerror) { 1936 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1937 PetscFunctionReturn(0); 1938 } 1939 if (snes->ops->solve != SNESSolveVI_SS) { 1940 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1941 } else { 1942 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1943 } 1944 1945 ierr = VecNormBegin(y,NORM_2,ynorm);CHKERRQ(ierr); 1946 ierr = VecNormEnd(y,NORM_2,ynorm);CHKERRQ(ierr); 1947 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1948 } 1949 } 1950 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1951 PetscFunctionReturn(0); 1952 } 1953 1954 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*/ 1955 /* -------------------------------------------------------------------------- */ 1956 EXTERN_C_BEGIN 1957 #undef __FUNCT__ 1958 #define __FUNCT__ "SNESLineSearchSet_VI" 1959 PetscErrorCode SNESLineSearchSet_VI(SNES snes,FCN2 func,void *lsctx) 1960 { 1961 PetscFunctionBegin; 1962 ((SNES_VI *)(snes->data))->LineSearch = func; 1963 ((SNES_VI *)(snes->data))->lsP = lsctx; 1964 PetscFunctionReturn(0); 1965 } 1966 EXTERN_C_END 1967 1968 /* -------------------------------------------------------------------------- */ 1969 EXTERN_C_BEGIN 1970 #undef __FUNCT__ 1971 #define __FUNCT__ "SNESLineSearchSetMonitor_VI" 1972 PetscErrorCode SNESLineSearchSetMonitor_VI(SNES snes,PetscBool flg) 1973 { 1974 SNES_VI *vi = (SNES_VI*)snes->data; 1975 PetscErrorCode ierr; 1976 1977 PetscFunctionBegin; 1978 if (flg && !vi->lsmonitor) { 1979 ierr = PetscViewerASCIIMonitorCreate(((PetscObject)snes)->comm,"stdout",((PetscObject)snes)->tablevel,&vi->lsmonitor);CHKERRQ(ierr); 1980 } else if (!flg && vi->lsmonitor) { 1981 ierr = PetscViewerASCIIMonitorDestroy(vi->lsmonitor);CHKERRQ(ierr); 1982 } 1983 PetscFunctionReturn(0); 1984 } 1985 EXTERN_C_END 1986 1987 /* 1988 SNESView_VI - Prints info from the SNESVI data structure. 1989 1990 Input Parameters: 1991 . SNES - the SNES context 1992 . viewer - visualization context 1993 1994 Application Interface Routine: SNESView() 1995 */ 1996 #undef __FUNCT__ 1997 #define __FUNCT__ "SNESView_VI" 1998 static PetscErrorCode SNESView_VI(SNES snes,PetscViewer viewer) 1999 { 2000 SNES_VI *vi = (SNES_VI *)snes->data; 2001 const char *cstr,*tstr; 2002 PetscErrorCode ierr; 2003 PetscBool iascii; 2004 2005 PetscFunctionBegin; 2006 ierr = PetscTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr); 2007 if (iascii) { 2008 if (vi->LineSearch == SNESLineSearchNo_VI) cstr = "SNESLineSearchNo"; 2009 else if (vi->LineSearch == SNESLineSearchQuadratic_VI) cstr = "SNESLineSearchQuadratic"; 2010 else if (vi->LineSearch == SNESLineSearchCubic_VI) cstr = "SNESLineSearchCubic"; 2011 else cstr = "unknown"; 2012 if (snes->ops->solve == SNESSolveVI_SS) tstr = "Semismooth"; 2013 else if (snes->ops->solve == SNESSolveVI_RS) tstr = "Reduced Space"; 2014 else if (snes->ops->solve == SNESSolveVI_RS2) tstr = "Augmented Space"; 2015 else tstr = "unknown"; 2016 ierr = PetscViewerASCIIPrintf(viewer," VI algorithm: %s\n",tstr);CHKERRQ(ierr); 2017 ierr = PetscViewerASCIIPrintf(viewer," line search variant: %s\n",cstr);CHKERRQ(ierr); 2018 ierr = PetscViewerASCIIPrintf(viewer," alpha=%G, maxstep=%G, minlambda=%G\n",vi->alpha,vi->maxstep,vi->minlambda);CHKERRQ(ierr); 2019 } else { 2020 SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Viewer type %s not supported for SNES EQ VI",((PetscObject)viewer)->type_name); 2021 } 2022 PetscFunctionReturn(0); 2023 } 2024 2025 #undef __FUNCT__ 2026 #define __FUNCT__ "SNESVISetVariableBounds" 2027 /*@ 2028 SNESVISetVariableBounds - Sets the lower and upper bounds for the solution vector. xl <= x <= xu. 2029 2030 Input Parameters: 2031 . snes - the SNES context. 2032 . xl - lower bound. 2033 . xu - upper bound. 2034 2035 Notes: 2036 If this routine is not called then the lower and upper bounds are set to 2037 PETSC_VI_INF and PETSC_VI_NINF respectively during SNESSetUp(). 2038 2039 @*/ 2040 PetscErrorCode SNESVISetVariableBounds(SNES snes, Vec xl, Vec xu) 2041 { 2042 SNES_VI *vi = (SNES_VI*)snes->data; 2043 2044 PetscFunctionBegin; 2045 PetscValidHeaderSpecific(snes,SNES_CLASSID,1); 2046 PetscValidHeaderSpecific(xl,VEC_CLASSID,2); 2047 PetscValidHeaderSpecific(xu,VEC_CLASSID,3); 2048 if (!snes->vec_func) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Must call SNESSetFunction() first"); 2049 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); 2050 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); 2051 2052 vi->usersetxbounds = PETSC_TRUE; 2053 vi->xl = xl; 2054 vi->xu = xu; 2055 PetscFunctionReturn(0); 2056 } 2057 2058 /* -------------------------------------------------------------------------- */ 2059 /* 2060 SNESSetFromOptions_VI - Sets various parameters for the SNESVI method. 2061 2062 Input Parameter: 2063 . snes - the SNES context 2064 2065 Application Interface Routine: SNESSetFromOptions() 2066 */ 2067 #undef __FUNCT__ 2068 #define __FUNCT__ "SNESSetFromOptions_VI" 2069 static PetscErrorCode SNESSetFromOptions_VI(SNES snes) 2070 { 2071 SNES_VI *vi = (SNES_VI *)snes->data; 2072 const char *lses[] = {"basic","basicnonorms","quadratic","cubic"}; 2073 const char *vies[] = {"ss","rs","rs2"}; 2074 PetscErrorCode ierr; 2075 PetscInt indx; 2076 PetscBool flg,set,flg2; 2077 2078 PetscFunctionBegin; 2079 ierr = PetscOptionsHead("SNES semismooth method options");CHKERRQ(ierr); 2080 ierr = PetscOptionsBool("-snes_vi_monitor","Monitor all non-active variables","None",PETSC_FALSE,&flg,0);CHKERRQ(ierr); 2081 if (flg) { 2082 ierr = SNESMonitorSet(snes,SNESMonitorVI,0,0);CHKERRQ(ierr); 2083 } 2084 ierr = PetscOptionsReal("-snes_ls_alpha","Function norm must decrease by","None",vi->alpha,&vi->alpha,0);CHKERRQ(ierr); 2085 ierr = PetscOptionsReal("-snes_ls_maxstep","Step must be less than","None",vi->maxstep,&vi->maxstep,0);CHKERRQ(ierr); 2086 ierr = PetscOptionsReal("-snes_ls_minlambda","Minimum lambda allowed","None",vi->minlambda,&vi->minlambda,0);CHKERRQ(ierr); 2087 ierr = PetscOptionsReal("-snes_vi_const_tol","constraint tolerance","None",vi->const_tol,&vi->const_tol,0);CHKERRQ(ierr); 2088 ierr = PetscOptionsBool("-snes_ls_monitor","Print progress of line searches","SNESLineSearchSetMonitor",vi->lsmonitor ? PETSC_TRUE : PETSC_FALSE,&flg,&set);CHKERRQ(ierr); 2089 if (set) {ierr = SNESLineSearchSetMonitor(snes,flg);CHKERRQ(ierr);} 2090 ierr = PetscOptionsEList("-snes_vi_type","Semismooth algorithm used","",vies,3,"ss",&indx,&flg2);CHKERRQ(ierr); 2091 if (flg2) { 2092 switch (indx) { 2093 case 0: 2094 snes->ops->solve = SNESSolveVI_SS; 2095 break; 2096 case 1: 2097 snes->ops->solve = SNESSolveVI_RS; 2098 break; 2099 case 2: 2100 snes->ops->solve = SNESSolveVI_RS2; 2101 } 2102 } 2103 ierr = PetscOptionsEList("-snes_ls","Line search used","SNESLineSearchSet",lses,4,"basic",&indx,&flg);CHKERRQ(ierr); 2104 if (flg) { 2105 switch (indx) { 2106 case 0: 2107 ierr = SNESLineSearchSet(snes,SNESLineSearchNo_VI,PETSC_NULL);CHKERRQ(ierr); 2108 break; 2109 case 1: 2110 ierr = SNESLineSearchSet(snes,SNESLineSearchNoNorms_VI,PETSC_NULL);CHKERRQ(ierr); 2111 break; 2112 case 2: 2113 ierr = SNESLineSearchSet(snes,SNESLineSearchQuadratic_VI,PETSC_NULL);CHKERRQ(ierr); 2114 break; 2115 case 3: 2116 ierr = SNESLineSearchSet(snes,SNESLineSearchCubic_VI,PETSC_NULL);CHKERRQ(ierr); 2117 break; 2118 } 2119 } 2120 ierr = PetscOptionsTail();CHKERRQ(ierr); 2121 PetscFunctionReturn(0); 2122 } 2123 /* -------------------------------------------------------------------------- */ 2124 /*MC 2125 SNESVI - Semismooth newton method based nonlinear solver that uses a line search 2126 2127 Options Database: 2128 + -snes_ls [cubic,quadratic,basic,basicnonorms] - Selects line search 2129 . -snes_ls_alpha <alpha> - Sets alpha 2130 . -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) 2131 . -snes_ls_minlambda <minlambda> - Sets the minimum lambda the line search will use minlambda / max_i ( y[i]/x[i] ) 2132 - -snes_ls_monitor - print information about progress of line searches 2133 2134 2135 Level: beginner 2136 2137 .seealso: SNESCreate(), SNES, SNESSetType(), SNESTR, SNESLineSearchSet(), 2138 SNESLineSearchSetPostCheck(), SNESLineSearchNo(), SNESLineSearchCubic(), SNESLineSearchQuadratic(), 2139 SNESLineSearchSet(), SNESLineSearchNoNorms(), SNESLineSearchSetPreCheck(), SNESLineSearchSetParams(), SNESLineSearchGetParams() 2140 2141 M*/ 2142 EXTERN_C_BEGIN 2143 #undef __FUNCT__ 2144 #define __FUNCT__ "SNESCreate_VI" 2145 PetscErrorCode SNESCreate_VI(SNES snes) 2146 { 2147 PetscErrorCode ierr; 2148 SNES_VI *vi; 2149 2150 PetscFunctionBegin; 2151 snes->ops->setup = SNESSetUp_VI; 2152 snes->ops->solve = SNESSolveVI_SS; 2153 snes->ops->destroy = SNESDestroy_VI; 2154 snes->ops->setfromoptions = SNESSetFromOptions_VI; 2155 snes->ops->view = SNESView_VI; 2156 snes->ops->converged = SNESDefaultConverged_VI; 2157 2158 ierr = PetscNewLog(snes,SNES_VI,&vi);CHKERRQ(ierr); 2159 snes->data = (void*)vi; 2160 vi->alpha = 1.e-4; 2161 vi->maxstep = 1.e8; 2162 vi->minlambda = 1.e-12; 2163 vi->LineSearch = SNESLineSearchNo_VI; 2164 vi->lsP = PETSC_NULL; 2165 vi->postcheckstep = PETSC_NULL; 2166 vi->postcheck = PETSC_NULL; 2167 vi->precheckstep = PETSC_NULL; 2168 vi->precheck = PETSC_NULL; 2169 vi->const_tol = 2.2204460492503131e-16; 2170 vi->checkredundancy = PETSC_NULL; 2171 2172 ierr = PetscObjectComposeFunctionDynamic((PetscObject)snes,"SNESLineSearchSetMonitor_C","SNESLineSearchSetMonitor_VI",SNESLineSearchSetMonitor_VI);CHKERRQ(ierr); 2173 ierr = PetscObjectComposeFunctionDynamic((PetscObject)snes,"SNESLineSearchSet_C","SNESLineSearchSet_VI",SNESLineSearchSet_VI);CHKERRQ(ierr); 2174 2175 PetscFunctionReturn(0); 2176 } 2177 EXTERN_C_END 2178