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] <= SNES_VI_NINF) && (u[i] >= SNES_VI_INF)) { /* no constraints on variable */ 230 phi_arr[i] = f_arr[i]; 231 } else if (l[i] <= SNES_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] >= SNES_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] <= SNES_VI_NINF) && (u[i] >= SNES_VI_INF)) {/* no constraints on variable */ 275 da[i] = 0; 276 db[i] = 1; 277 } else if (l[i] <= SNES_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] >= SNES_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 ierr = SNESMonitor(snes,0,vi->phinorm);CHKERRQ(ierr); 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 ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr); 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 ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr); 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 ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr); 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*),void *ctx) 1010 { 1011 SNES_VI *vi = (SNES_VI*)snes->data; 1012 1013 PetscFunctionBegin; 1014 PetscValidHeaderSpecific(snes,SNES_CLASSID,1); 1015 vi->checkredundancy = func; 1016 vi->ctxP = ctx; 1017 PetscFunctionReturn(0); 1018 } 1019 1020 #if defined(PETSC_HAVE_MATLAB_ENGINE) 1021 #include <engine.h> 1022 #include <mex.h> 1023 typedef struct {char *funcname; mxArray *ctx;} SNESMatlabContext; 1024 1025 #undef __FUNCT__ 1026 #define __FUNCT__ "SNESVIRedundancyCheck_Matlab" 1027 PetscErrorCode SNESVIRedundancyCheck_Matlab(SNES snes,IS is_act,IS* is_redact,void* ctx) 1028 { 1029 PetscErrorCode ierr; 1030 SNESMatlabContext *sctx = (SNESMatlabContext*)ctx; 1031 int nlhs = 1, nrhs = 5; 1032 mxArray *plhs[1], *prhs[5]; 1033 long long int l1 = 0, l2 = 0, ls = 0; 1034 PetscInt *indices=PETSC_NULL; 1035 1036 PetscFunctionBegin; 1037 PetscValidHeaderSpecific(snes,SNES_CLASSID,1); 1038 PetscValidHeaderSpecific(is_act,IS_CLASSID,2); 1039 PetscValidPointer(is_redact,3); 1040 PetscCheckSameComm(snes,1,is_act,2); 1041 1042 /* Create IS for reduced active set of size 0, its size and indices will 1043 bet set by the Matlab function */ 1044 ierr = ISCreateGeneral(((PetscObject)snes)->comm,0,indices,PETSC_OWN_POINTER,is_redact);CHKERRQ(ierr); 1045 /* call Matlab function in ctx */ 1046 ierr = PetscMemcpy(&ls,&snes,sizeof(snes));CHKERRQ(ierr); 1047 ierr = PetscMemcpy(&l1,&is_act,sizeof(is_act));CHKERRQ(ierr); 1048 ierr = PetscMemcpy(&l2,is_redact,sizeof(is_act));CHKERRQ(ierr); 1049 prhs[0] = mxCreateDoubleScalar((double)ls); 1050 prhs[1] = mxCreateDoubleScalar((double)l1); 1051 prhs[2] = mxCreateDoubleScalar((double)l2); 1052 prhs[3] = mxCreateString(sctx->funcname); 1053 prhs[4] = sctx->ctx; 1054 ierr = mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscSNESVIRedundancyCheckInternal");CHKERRQ(ierr); 1055 ierr = mxGetScalar(plhs[0]);CHKERRQ(ierr); 1056 mxDestroyArray(prhs[0]); 1057 mxDestroyArray(prhs[1]); 1058 mxDestroyArray(prhs[2]); 1059 mxDestroyArray(prhs[3]); 1060 mxDestroyArray(plhs[0]); 1061 PetscFunctionReturn(0); 1062 } 1063 1064 #undef __FUNCT__ 1065 #define __FUNCT__ "SNESVISetRedundancyCheckMatlab" 1066 PetscErrorCode SNESVISetRedundancyCheckMatlab(SNES snes,const char* func,mxArray* ctx) 1067 { 1068 PetscErrorCode ierr; 1069 SNESMatlabContext *sctx; 1070 1071 PetscFunctionBegin; 1072 /* currently sctx is memory bleed */ 1073 ierr = PetscMalloc(sizeof(SNESMatlabContext),&sctx);CHKERRQ(ierr); 1074 ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr); 1075 sctx->ctx = mxDuplicateArray(ctx); 1076 ierr = SNESVISetRedundancyCheck(snes,SNESVIRedundancyCheck_Matlab,sctx);CHKERRQ(ierr); 1077 PetscFunctionReturn(0); 1078 } 1079 1080 #endif 1081 1082 1083 /* Variational Inequality solver using augmented space method. It does the opposite of the 1084 reduced space method i.e. it identifies the active set variables and instead of discarding 1085 them it augments the original system by introducing additional equality 1086 constraint equations for active set variables. The user can optionally provide an IS for 1087 a subset of 'redundant' active set variables which will treated as free variables. 1088 Specific implementation for Allen-Cahn problem 1089 */ 1090 #undef __FUNCT__ 1091 #define __FUNCT__ "SNESSolveVI_RS2" 1092 PetscErrorCode SNESSolveVI_RS2(SNES snes) 1093 { 1094 SNES_VI *vi = (SNES_VI*)snes->data; 1095 PetscErrorCode ierr; 1096 PetscInt maxits,i,lits; 1097 PetscBool lssucceed; 1098 MatStructure flg = DIFFERENT_NONZERO_PATTERN; 1099 PetscReal fnorm,gnorm,xnorm=0,ynorm; 1100 Vec Y,X,F,G,W; 1101 KSPConvergedReason kspreason; 1102 1103 PetscFunctionBegin; 1104 snes->numFailures = 0; 1105 snes->numLinearSolveFailures = 0; 1106 snes->reason = SNES_CONVERGED_ITERATING; 1107 1108 maxits = snes->max_its; /* maximum number of iterations */ 1109 X = snes->vec_sol; /* solution vector */ 1110 F = snes->vec_func; /* residual vector */ 1111 Y = snes->work[0]; /* work vectors */ 1112 G = snes->work[1]; 1113 W = snes->work[2]; 1114 1115 ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); 1116 snes->iter = 0; 1117 snes->norm = 0.0; 1118 ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); 1119 1120 ierr = SNESVIProjectOntoBounds(snes,X);CHKERRQ(ierr); 1121 ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); 1122 if (snes->domainerror) { 1123 snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; 1124 PetscFunctionReturn(0); 1125 } 1126 ierr = SNESVIComputeInactiveSetFnorm(snes,F,X,&fnorm);CHKERRQ(ierr); 1127 ierr = VecNormBegin(X,NORM_2,&xnorm);CHKERRQ(ierr); /* xnorm <- ||x|| */ 1128 ierr = VecNormEnd(X,NORM_2,&xnorm);CHKERRQ(ierr); 1129 if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1130 1131 ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); 1132 snes->norm = fnorm; 1133 ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); 1134 SNESLogConvHistory(snes,fnorm,0); 1135 ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr); 1136 1137 /* set parameter for default relative tolerance convergence test */ 1138 snes->ttol = fnorm*snes->rtol; 1139 /* test convergence */ 1140 ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); 1141 if (snes->reason) PetscFunctionReturn(0); 1142 1143 for (i=0; i<maxits; i++) { 1144 IS IS_act,IS_inact; /* _act -> active set _inact -> inactive set */ 1145 IS IS_redact; /* redundant active set */ 1146 Mat J_aug,Jpre_aug; 1147 Vec F_aug,Y_aug; 1148 PetscInt nis_redact,nis_act; 1149 const PetscInt *idx_redact,*idx_act; 1150 PetscInt k; 1151 PetscInt *idx_actkept=PETSC_NULL,nkept=0; /* list of kept active set */ 1152 PetscScalar *f,*f2; 1153 PetscBool isequal; 1154 PetscInt i1=0,j1=0; 1155 1156 /* Call general purpose update function */ 1157 if (snes->ops->update) { 1158 ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr); 1159 } 1160 ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr); 1161 1162 /* Create active and inactive index sets */ 1163 ierr = SNESVICreateIndexSets_RS(snes,X,F,&IS_act,&IS_inact);CHKERRQ(ierr); 1164 1165 /* Get local active set size */ 1166 ierr = ISGetLocalSize(IS_act,&nis_act);CHKERRQ(ierr); 1167 ierr = ISGetIndices(IS_act,&idx_act);CHKERRQ(ierr); 1168 if(nis_act) { 1169 if(vi->checkredundancy) { 1170 (*vi->checkredundancy)(snes,IS_act,&IS_redact,vi->ctxP); 1171 } 1172 1173 if(!IS_redact) { 1174 /* User called checkredundancy function but didn't create IS_redact because 1175 there were no redundant active set variables */ 1176 /* Copy over all active set indices to the list */ 1177 ierr = PetscMalloc(nis_act*sizeof(PetscInt),&idx_actkept);CHKERRQ(ierr); 1178 for(k=0;k < nis_act;k++) idx_actkept[k] = idx_act[k]; 1179 nkept = nis_act; 1180 } else { 1181 ierr = ISGetLocalSize(IS_redact,&nis_redact);CHKERRQ(ierr); 1182 ierr = PetscMalloc((nis_act-nis_redact)*sizeof(PetscInt),&idx_actkept);CHKERRQ(ierr); 1183 1184 /* Create reduced active set list */ 1185 ierr = ISGetIndices(IS_act,&idx_act);CHKERRQ(ierr); 1186 ierr = ISGetIndices(IS_redact,&idx_redact);CHKERRQ(ierr); 1187 j1 = 0;nkept = 0; 1188 for(k=0;k<nis_act;k++) { 1189 if(j1 < nis_redact && idx_act[k] == idx_redact[j1]) j1++; 1190 else idx_actkept[nkept++] = idx_act[k]; 1191 } 1192 ierr = ISRestoreIndices(IS_act,&idx_act);CHKERRQ(ierr); 1193 ierr = ISRestoreIndices(IS_redact,&idx_redact);CHKERRQ(ierr); 1194 1195 ierr = ISDestroy(&IS_redact);CHKERRQ(ierr); 1196 } 1197 1198 /* Create augmented F and Y */ 1199 ierr = VecCreate(((PetscObject)snes)->comm,&F_aug);CHKERRQ(ierr); 1200 ierr = VecSetSizes(F_aug,F->map->n+nkept,PETSC_DECIDE);CHKERRQ(ierr); 1201 ierr = VecSetFromOptions(F_aug);CHKERRQ(ierr); 1202 ierr = VecDuplicate(F_aug,&Y_aug);CHKERRQ(ierr); 1203 1204 /* Copy over F to F_aug in the first n locations */ 1205 ierr = VecGetArray(F,&f);CHKERRQ(ierr); 1206 ierr = VecGetArray(F_aug,&f2);CHKERRQ(ierr); 1207 ierr = PetscMemcpy(f2,f,F->map->n*sizeof(PetscScalar));CHKERRQ(ierr); 1208 ierr = VecRestoreArray(F,&f);CHKERRQ(ierr); 1209 ierr = VecRestoreArray(F_aug,&f2);CHKERRQ(ierr); 1210 1211 /* Create the augmented jacobian matrix */ 1212 ierr = MatCreate(((PetscObject)snes)->comm,&J_aug);CHKERRQ(ierr); 1213 ierr = MatSetSizes(J_aug,X->map->n+nkept,X->map->n+nkept,PETSC_DECIDE,PETSC_DECIDE);CHKERRQ(ierr); 1214 ierr = MatSetFromOptions(J_aug);CHKERRQ(ierr); 1215 1216 1217 { /* local vars */ 1218 /* Preallocate augmented matrix and set values in it...Doing only sequential case first*/ 1219 PetscInt ncols; 1220 const PetscInt *cols; 1221 const PetscScalar *vals; 1222 PetscScalar value=1.0; 1223 PetscInt row,col; 1224 PetscInt *d_nnz; 1225 1226 ierr = PetscMalloc((X->map->n+nkept)*sizeof(PetscInt),&d_nnz);CHKERRQ(ierr); 1227 ierr = PetscMemzero(d_nnz,(X->map->n+nkept)*sizeof(PetscInt));CHKERRQ(ierr); 1228 for(row=0;row<snes->jacobian->rmap->n;row++) { 1229 ierr = MatGetRow(snes->jacobian,row,&ncols,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr); 1230 d_nnz[row] += ncols; 1231 ierr = MatRestoreRow(snes->jacobian,row,&ncols,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr); 1232 } 1233 1234 for(k=0;k<nkept;k++) { 1235 d_nnz[idx_actkept[k]] += 1; 1236 d_nnz[snes->jacobian->rmap->n+k] += 1; 1237 } 1238 ierr = MatSeqAIJSetPreallocation(J_aug,PETSC_NULL,d_nnz);CHKERRQ(ierr); 1239 1240 ierr = PetscFree(d_nnz);CHKERRQ(ierr); 1241 1242 /* Set the original jacobian matrix in J_aug */ 1243 for(row=0;row<snes->jacobian->rmap->n;row++) { 1244 ierr = MatGetRow(snes->jacobian,row,&ncols,&cols,&vals);CHKERRQ(ierr); 1245 ierr = MatSetValues(J_aug,1,&row,ncols,cols,vals,INSERT_VALUES);CHKERRQ(ierr); 1246 ierr = MatRestoreRow(snes->jacobian,row,&ncols,&cols,&vals);CHKERRQ(ierr); 1247 } 1248 /* Add the augmented part */ 1249 for(k=0;k<nkept;k++) { 1250 row = idx_actkept[k]; 1251 col = snes->jacobian->rmap->n+k; 1252 ierr = MatSetValues(J_aug,1,&row,1,&col,&value,INSERT_VALUES);CHKERRQ(ierr); 1253 ierr = MatSetValues(J_aug,1,&col,1,&row,&value,INSERT_VALUES);CHKERRQ(ierr); 1254 } 1255 ierr = MatAssemblyBegin(J_aug,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 1256 ierr = MatAssemblyEnd(J_aug,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 1257 /* Only considering prejac = jac for now */ 1258 Jpre_aug = J_aug; 1259 } /* local vars*/ 1260 } else { 1261 F_aug = F; J_aug = snes->jacobian; Y_aug = Y; Jpre_aug = snes->jacobian_pre; 1262 } 1263 1264 ierr = ISEqual(vi->IS_inact_prev,IS_inact,&isequal);CHKERRQ(ierr); 1265 if (!isequal) { 1266 ierr = SNESVIResetPCandKSP(snes,J_aug,Jpre_aug);CHKERRQ(ierr); 1267 } 1268 ierr = KSPSetOperators(snes->ksp,J_aug,Jpre_aug,flg);CHKERRQ(ierr); 1269 ierr = KSPSetUp(snes->ksp);CHKERRQ(ierr); 1270 /* { 1271 PC pc; 1272 PetscBool flg; 1273 ierr = KSPGetPC(snes->ksp,&pc);CHKERRQ(ierr); 1274 ierr = PetscTypeCompare((PetscObject)pc,PCFIELDSPLIT,&flg);CHKERRQ(ierr); 1275 if (flg) { 1276 KSP *subksps; 1277 ierr = PCFieldSplitGetSubKSP(pc,PETSC_NULL,&subksps);CHKERRQ(ierr); 1278 ierr = KSPGetPC(subksps[0],&pc);CHKERRQ(ierr); 1279 ierr = PetscFree(subksps);CHKERRQ(ierr); 1280 ierr = PetscTypeCompare((PetscObject)pc,PCBJACOBI,&flg);CHKERRQ(ierr); 1281 if (flg) { 1282 PetscInt n,N = 101*101,j,cnts[3] = {0,0,0}; 1283 const PetscInt *ii; 1284 1285 ierr = ISGetSize(IS_inact,&n);CHKERRQ(ierr); 1286 ierr = ISGetIndices(IS_inact,&ii);CHKERRQ(ierr); 1287 for (j=0; j<n; j++) { 1288 if (ii[j] < N) cnts[0]++; 1289 else if (ii[j] < 2*N) cnts[1]++; 1290 else if (ii[j] < 3*N) cnts[2]++; 1291 } 1292 ierr = ISRestoreIndices(IS_inact,&ii);CHKERRQ(ierr); 1293 1294 ierr = PCBJacobiSetTotalBlocks(pc,3,cnts);CHKERRQ(ierr); 1295 } 1296 } 1297 } 1298 */ 1299 ierr = SNES_KSPSolve(snes,snes->ksp,F_aug,Y_aug);CHKERRQ(ierr); 1300 ierr = KSPGetConvergedReason(snes->ksp,&kspreason);CHKERRQ(ierr); 1301 if (kspreason < 0) { 1302 if (++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) { 1303 ierr = PetscInfo2(snes,"iter=%D, number linear solve failures %D greater than current SNES allowed, stopping solve\n",snes->iter,snes->numLinearSolveFailures);CHKERRQ(ierr); 1304 snes->reason = SNES_DIVERGED_LINEAR_SOLVE; 1305 break; 1306 } 1307 } 1308 1309 if(nis_act) { 1310 PetscScalar *y1,*y2; 1311 ierr = VecGetArray(Y,&y1);CHKERRQ(ierr); 1312 ierr = VecGetArray(Y_aug,&y2);CHKERRQ(ierr); 1313 /* Copy over inactive Y_aug to Y */ 1314 j1 = 0; 1315 for(i1=Y->map->rstart;i1 < Y->map->rend;i1++) { 1316 if(j1 < nkept && idx_actkept[j1] == i1) j1++; 1317 else y1[i1-Y->map->rstart] = y2[i1-Y->map->rstart]; 1318 } 1319 ierr = VecRestoreArray(Y,&y1);CHKERRQ(ierr); 1320 ierr = VecRestoreArray(Y_aug,&y2);CHKERRQ(ierr); 1321 1322 ierr = VecDestroy(&F_aug);CHKERRQ(ierr); 1323 ierr = VecDestroy(&Y_aug);CHKERRQ(ierr); 1324 ierr = MatDestroy(&J_aug);CHKERRQ(ierr); 1325 ierr = PetscFree(idx_actkept);CHKERRQ(ierr); 1326 } 1327 1328 if (!isequal) { 1329 ierr = ISDestroy(&vi->IS_inact_prev);CHKERRQ(ierr); 1330 ierr = ISDuplicate(IS_inact,&vi->IS_inact_prev);CHKERRQ(ierr); 1331 } 1332 ierr = ISDestroy(&IS_inact);CHKERRQ(ierr); 1333 1334 ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr); 1335 snes->linear_its += lits; 1336 ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr); 1337 /* 1338 if (vi->precheckstep) { 1339 PetscBool changed_y = PETSC_FALSE; 1340 ierr = (*vi->precheckstep)(snes,X,Y,vi->precheck,&changed_y);CHKERRQ(ierr); 1341 } 1342 1343 if (PetscLogPrintInfo){ 1344 ierr = SNESVICheckResidual_Private(snes,snes->jacobian,F,Y,G,W);CHKERRQ(ierr); 1345 } 1346 */ 1347 /* Compute a (scaled) negative update in the line search routine: 1348 Y <- X - lambda*Y 1349 and evaluate G = function(Y) (depends on the line search). 1350 */ 1351 ierr = VecCopy(Y,snes->vec_sol_update);CHKERRQ(ierr); 1352 ynorm = 1; gnorm = fnorm; 1353 ierr = (*vi->LineSearch)(snes,vi->lsP,X,F,G,Y,W,fnorm,xnorm,&ynorm,&gnorm,&lssucceed);CHKERRQ(ierr); 1354 ierr = PetscInfo4(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lssucceed=%d\n",fnorm,gnorm,ynorm,(int)lssucceed);CHKERRQ(ierr); 1355 if (snes->reason == SNES_DIVERGED_FUNCTION_COUNT) break; 1356 if (snes->domainerror) { 1357 snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; 1358 PetscFunctionReturn(0); 1359 } 1360 if (!lssucceed) { 1361 if (++snes->numFailures >= snes->maxFailures) { 1362 PetscBool ismin; 1363 snes->reason = SNES_DIVERGED_LINE_SEARCH; 1364 ierr = SNESVICheckLocalMin_Private(snes,snes->jacobian,G,W,gnorm,&ismin);CHKERRQ(ierr); 1365 if (ismin) snes->reason = SNES_DIVERGED_LOCAL_MIN; 1366 break; 1367 } 1368 } 1369 /* Update function and solution vectors */ 1370 fnorm = gnorm; 1371 ierr = VecCopy(G,F);CHKERRQ(ierr); 1372 ierr = VecCopy(W,X);CHKERRQ(ierr); 1373 /* Monitor convergence */ 1374 ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); 1375 snes->iter = i+1; 1376 snes->norm = fnorm; 1377 ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); 1378 SNESLogConvHistory(snes,snes->norm,lits); 1379 ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr); 1380 /* Test for convergence, xnorm = || X || */ 1381 if (snes->ops->converged != SNESSkipConverged) { ierr = VecNorm(X,NORM_2,&xnorm);CHKERRQ(ierr); } 1382 ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); 1383 if (snes->reason) break; 1384 } 1385 if (i == maxits) { 1386 ierr = PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",maxits);CHKERRQ(ierr); 1387 if(!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT; 1388 } 1389 PetscFunctionReturn(0); 1390 } 1391 1392 /* -------------------------------------------------------------------------- */ 1393 /* 1394 SNESSetUp_VI - Sets up the internal data structures for the later use 1395 of the SNESVI nonlinear solver. 1396 1397 Input Parameter: 1398 . snes - the SNES context 1399 . x - the solution vector 1400 1401 Application Interface Routine: SNESSetUp() 1402 1403 Notes: 1404 For basic use of the SNES solvers, the user need not explicitly call 1405 SNESSetUp(), since these actions will automatically occur during 1406 the call to SNESSolve(). 1407 */ 1408 #undef __FUNCT__ 1409 #define __FUNCT__ "SNESSetUp_VI" 1410 PetscErrorCode SNESSetUp_VI(SNES snes) 1411 { 1412 PetscErrorCode ierr; 1413 SNES_VI *vi = (SNES_VI*) snes->data; 1414 PetscInt i_start[3],i_end[3]; 1415 1416 PetscFunctionBegin; 1417 1418 ierr = SNESDefaultGetWork(snes,3);CHKERRQ(ierr); 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,SNES_VI_NINF);CHKERRQ(ierr); 1426 ierr = VecDuplicate(snes->vec_sol, &vi->xu); CHKERRQ(ierr); 1427 ierr = VecSet(vi->xu,SNES_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->ops->solve != SNESSolveVI_SS) { 1478 ierr = ISDestroy(&vi->IS_inact_prev); 1479 } 1480 1481 if (snes->ops->solve == SNESSolveVI_SS) { 1482 /* clear vectors */ 1483 ierr = VecDestroy(&vi->dpsi);CHKERRQ(ierr); 1484 ierr = VecDestroy(&vi->phi); CHKERRQ(ierr); 1485 ierr = VecDestroy(&vi->Da); CHKERRQ(ierr); 1486 ierr = VecDestroy(&vi->Db); CHKERRQ(ierr); 1487 ierr = VecDestroy(&vi->z); CHKERRQ(ierr); 1488 ierr = VecDestroy(&vi->t); CHKERRQ(ierr); 1489 } 1490 1491 if (!vi->usersetxbounds) { 1492 ierr = VecDestroy(&vi->xl); CHKERRQ(ierr); 1493 ierr = VecDestroy(&vi->xu); CHKERRQ(ierr); 1494 } 1495 1496 ierr = PetscViewerASCIIMonitorDestroy(&vi->lsmonitor);CHKERRQ(ierr); 1497 ierr = PetscFree(snes->data);CHKERRQ(ierr); 1498 1499 /* clear composed functions */ 1500 ierr = PetscObjectComposeFunctionDynamic((PetscObject)snes,"SNESLineSearchSet_C","",PETSC_NULL);CHKERRQ(ierr); 1501 ierr = PetscObjectComposeFunctionDynamic((PetscObject)snes,"SNESLineSearchSetMonitor_C","",PETSC_NULL);CHKERRQ(ierr); 1502 PetscFunctionReturn(0); 1503 } 1504 1505 /* -------------------------------------------------------------------------- */ 1506 #undef __FUNCT__ 1507 #define __FUNCT__ "SNESLineSearchNo_VI" 1508 1509 /* 1510 This routine does not actually do a line search but it takes a full newton 1511 step while ensuring that the new iterates remain within the constraints. 1512 1513 */ 1514 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) 1515 { 1516 PetscErrorCode ierr; 1517 SNES_VI *vi = (SNES_VI*)snes->data; 1518 PetscBool changed_w = PETSC_FALSE,changed_y = PETSC_FALSE; 1519 1520 PetscFunctionBegin; 1521 *flag = PETSC_TRUE; 1522 ierr = PetscLogEventBegin(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1523 ierr = VecNorm(y,NORM_2,ynorm);CHKERRQ(ierr); /* ynorm = || y || */ 1524 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); /* w <- x - y */ 1525 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1526 if (vi->postcheckstep) { 1527 ierr = (*vi->postcheckstep)(snes,x,y,w,vi->postcheck,&changed_y,&changed_w);CHKERRQ(ierr); 1528 } 1529 if (changed_y) { 1530 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); /* w <- x - y */ 1531 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1532 } 1533 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1534 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1535 if (!snes->domainerror) { 1536 if (snes->ops->solve != SNESSolveVI_SS) { 1537 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1538 } else { 1539 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); /* gnorm = || g || */ 1540 } 1541 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1542 } 1543 if (vi->lsmonitor) { 1544 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Using full step: fnorm %G gnorm %G\n",fnorm,*gnorm);CHKERRQ(ierr); 1545 } 1546 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1547 PetscFunctionReturn(0); 1548 } 1549 1550 /* -------------------------------------------------------------------------- */ 1551 #undef __FUNCT__ 1552 #define __FUNCT__ "SNESLineSearchNoNorms_VI" 1553 1554 /* 1555 This routine is a copy of SNESLineSearchNoNorms in snes/impls/ls/ls.c 1556 */ 1557 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) 1558 { 1559 PetscErrorCode ierr; 1560 SNES_VI *vi = (SNES_VI*)snes->data; 1561 PetscBool changed_w = PETSC_FALSE,changed_y = PETSC_FALSE; 1562 1563 PetscFunctionBegin; 1564 *flag = PETSC_TRUE; 1565 ierr = PetscLogEventBegin(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1566 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); /* w <- x - y */ 1567 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1568 if (vi->postcheckstep) { 1569 ierr = (*vi->postcheckstep)(snes,x,y,w,vi->postcheck,&changed_y,&changed_w);CHKERRQ(ierr); 1570 } 1571 if (changed_y) { 1572 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); /* w <- x - y */ 1573 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1574 } 1575 1576 /* don't evaluate function the last time through */ 1577 if (snes->iter < snes->max_its-1) { 1578 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1579 } 1580 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1581 PetscFunctionReturn(0); 1582 } 1583 1584 /* -------------------------------------------------------------------------- */ 1585 #undef __FUNCT__ 1586 #define __FUNCT__ "SNESLineSearchCubic_VI" 1587 /* 1588 This routine implements a cubic line search while doing a projection on the variable bounds 1589 */ 1590 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) 1591 { 1592 PetscReal initslope,lambdaprev,gnormprev,a,b,d,t1,t2,rellength; 1593 PetscReal minlambda,lambda,lambdatemp; 1594 #if defined(PETSC_USE_COMPLEX) 1595 PetscScalar cinitslope; 1596 #endif 1597 PetscErrorCode ierr; 1598 PetscInt count; 1599 SNES_VI *vi = (SNES_VI*)snes->data; 1600 PetscBool changed_w = PETSC_FALSE,changed_y = PETSC_FALSE; 1601 MPI_Comm comm; 1602 1603 PetscFunctionBegin; 1604 ierr = PetscObjectGetComm((PetscObject)snes,&comm);CHKERRQ(ierr); 1605 ierr = PetscLogEventBegin(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1606 *flag = PETSC_TRUE; 1607 1608 ierr = VecNorm(y,NORM_2,ynorm);CHKERRQ(ierr); 1609 if (*ynorm == 0.0) { 1610 if (vi->lsmonitor) { 1611 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Initial direction and size is 0\n");CHKERRQ(ierr); 1612 } 1613 *gnorm = fnorm; 1614 ierr = VecCopy(x,w);CHKERRQ(ierr); 1615 ierr = VecCopy(f,g);CHKERRQ(ierr); 1616 *flag = PETSC_FALSE; 1617 goto theend1; 1618 } 1619 if (*ynorm > vi->maxstep) { /* Step too big, so scale back */ 1620 if (vi->lsmonitor) { 1621 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Scaling step by %G old ynorm %G\n",vi->maxstep/(*ynorm),*ynorm);CHKERRQ(ierr); 1622 } 1623 ierr = VecScale(y,vi->maxstep/(*ynorm));CHKERRQ(ierr); 1624 *ynorm = vi->maxstep; 1625 } 1626 ierr = VecMaxPointwiseDivide(y,x,&rellength);CHKERRQ(ierr); 1627 minlambda = vi->minlambda/rellength; 1628 ierr = MatMult(snes->jacobian,y,w);CHKERRQ(ierr); 1629 #if defined(PETSC_USE_COMPLEX) 1630 ierr = VecDot(f,w,&cinitslope);CHKERRQ(ierr); 1631 initslope = PetscRealPart(cinitslope); 1632 #else 1633 ierr = VecDot(f,w,&initslope);CHKERRQ(ierr); 1634 #endif 1635 if (initslope > 0.0) initslope = -initslope; 1636 if (initslope == 0.0) initslope = -1.0; 1637 1638 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); 1639 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1640 if (snes->nfuncs >= snes->max_funcs) { 1641 ierr = PetscInfo(snes,"Exceeded maximum function evaluations, while checking full step length!\n");CHKERRQ(ierr); 1642 *flag = PETSC_FALSE; 1643 snes->reason = SNES_DIVERGED_FUNCTION_COUNT; 1644 goto theend1; 1645 } 1646 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1647 if (snes->ops->solve != SNESSolveVI_SS) { 1648 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1649 } else { 1650 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1651 } 1652 if (snes->domainerror) { 1653 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1654 PetscFunctionReturn(0); 1655 } 1656 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1657 ierr = PetscInfo2(snes,"Initial fnorm %G gnorm %G\n",fnorm,*gnorm);CHKERRQ(ierr); 1658 if (.5*(*gnorm)*(*gnorm) <= .5*fnorm*fnorm + vi->alpha*initslope) { /* Sufficient reduction */ 1659 if (vi->lsmonitor) { 1660 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Using full step: fnorm %G gnorm %G\n",fnorm,*gnorm);CHKERRQ(ierr); 1661 } 1662 goto theend1; 1663 } 1664 1665 /* Fit points with quadratic */ 1666 lambda = 1.0; 1667 lambdatemp = -initslope/((*gnorm)*(*gnorm) - fnorm*fnorm - 2.0*initslope); 1668 lambdaprev = lambda; 1669 gnormprev = *gnorm; 1670 if (lambdatemp > .5*lambda) lambdatemp = .5*lambda; 1671 if (lambdatemp <= .1*lambda) lambda = .1*lambda; 1672 else lambda = lambdatemp; 1673 1674 ierr = VecWAXPY(w,-lambda,y,x);CHKERRQ(ierr); 1675 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1676 if (snes->nfuncs >= snes->max_funcs) { 1677 ierr = PetscInfo1(snes,"Exceeded maximum function evaluations, while attempting quadratic backtracking! %D \n",snes->nfuncs);CHKERRQ(ierr); 1678 *flag = PETSC_FALSE; 1679 snes->reason = SNES_DIVERGED_FUNCTION_COUNT; 1680 goto theend1; 1681 } 1682 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1683 if (snes->ops->solve != SNESSolveVI_SS) { 1684 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1685 } else { 1686 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1687 } 1688 if (snes->domainerror) { 1689 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1690 PetscFunctionReturn(0); 1691 } 1692 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1693 if (vi->lsmonitor) { 1694 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: gnorm after quadratic fit %G\n",*gnorm);CHKERRQ(ierr); 1695 } 1696 if (.5*(*gnorm)*(*gnorm) < .5*fnorm*fnorm + lambda*vi->alpha*initslope) { /* sufficient reduction */ 1697 if (vi->lsmonitor) { 1698 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Quadratically determined step, lambda=%18.16e\n",lambda);CHKERRQ(ierr); 1699 } 1700 goto theend1; 1701 } 1702 1703 /* Fit points with cubic */ 1704 count = 1; 1705 while (PETSC_TRUE) { 1706 if (lambda <= minlambda) { 1707 if (vi->lsmonitor) { 1708 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: unable to find good step length! After %D tries \n",count);CHKERRQ(ierr); 1709 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); 1710 } 1711 *flag = PETSC_FALSE; 1712 break; 1713 } 1714 t1 = .5*((*gnorm)*(*gnorm) - fnorm*fnorm) - lambda*initslope; 1715 t2 = .5*(gnormprev*gnormprev - fnorm*fnorm) - lambdaprev*initslope; 1716 a = (t1/(lambda*lambda) - t2/(lambdaprev*lambdaprev))/(lambda-lambdaprev); 1717 b = (-lambdaprev*t1/(lambda*lambda) + lambda*t2/(lambdaprev*lambdaprev))/(lambda-lambdaprev); 1718 d = b*b - 3*a*initslope; 1719 if (d < 0.0) d = 0.0; 1720 if (a == 0.0) { 1721 lambdatemp = -initslope/(2.0*b); 1722 } else { 1723 lambdatemp = (-b + sqrt(d))/(3.0*a); 1724 } 1725 lambdaprev = lambda; 1726 gnormprev = *gnorm; 1727 if (lambdatemp > .5*lambda) lambdatemp = .5*lambda; 1728 if (lambdatemp <= .1*lambda) lambda = .1*lambda; 1729 else lambda = lambdatemp; 1730 ierr = VecWAXPY(w,-lambda,y,x);CHKERRQ(ierr); 1731 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1732 if (snes->nfuncs >= snes->max_funcs) { 1733 ierr = PetscInfo1(snes,"Exceeded maximum function evaluations, while looking for good step length! %D \n",count);CHKERRQ(ierr); 1734 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); 1735 *flag = PETSC_FALSE; 1736 snes->reason = SNES_DIVERGED_FUNCTION_COUNT; 1737 break; 1738 } 1739 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1740 if (snes->ops->solve != SNESSolveVI_SS) { 1741 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1742 } else { 1743 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1744 } 1745 if (snes->domainerror) { 1746 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1747 PetscFunctionReturn(0); 1748 } 1749 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1750 if (.5*(*gnorm)*(*gnorm) < .5*fnorm*fnorm + lambda*vi->alpha*initslope) { /* is reduction enough? */ 1751 if (vi->lsmonitor) { 1752 ierr = PetscPrintf(comm," Line search: Cubically determined step, current gnorm %G lambda=%18.16e\n",*gnorm,lambda);CHKERRQ(ierr); 1753 } 1754 break; 1755 } else { 1756 if (vi->lsmonitor) { 1757 ierr = PetscPrintf(comm," Line search: Cubic step no good, shrinking lambda, current gnorm %G lambda=%18.16e\n",*gnorm,lambda);CHKERRQ(ierr); 1758 } 1759 } 1760 count++; 1761 } 1762 theend1: 1763 /* Optional user-defined check for line search step validity */ 1764 if (vi->postcheckstep && *flag) { 1765 ierr = (*vi->postcheckstep)(snes,x,y,w,vi->postcheck,&changed_y,&changed_w);CHKERRQ(ierr); 1766 if (changed_y) { 1767 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); 1768 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1769 } 1770 if (changed_y || changed_w) { /* recompute the function if the step has changed */ 1771 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1772 if (snes->ops->solve != SNESSolveVI_SS) { 1773 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1774 } else { 1775 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1776 } 1777 if (snes->domainerror) { 1778 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1779 PetscFunctionReturn(0); 1780 } 1781 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1782 ierr = VecNormBegin(y,NORM_2,ynorm);CHKERRQ(ierr); 1783 ierr = VecNormEnd(y,NORM_2,ynorm);CHKERRQ(ierr); 1784 } 1785 } 1786 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1787 PetscFunctionReturn(0); 1788 } 1789 1790 #undef __FUNCT__ 1791 #define __FUNCT__ "SNESLineSearchQuadratic_VI" 1792 /* 1793 This routine does a quadratic line search while keeping the iterates within the variable bounds 1794 */ 1795 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) 1796 { 1797 /* 1798 Note that for line search purposes we work with with the related 1799 minimization problem: 1800 min z(x): R^n -> R, 1801 where z(x) = .5 * fnorm*fnorm,and fnorm = || f ||_2. 1802 */ 1803 PetscReal initslope,minlambda,lambda,lambdatemp,rellength; 1804 #if defined(PETSC_USE_COMPLEX) 1805 PetscScalar cinitslope; 1806 #endif 1807 PetscErrorCode ierr; 1808 PetscInt count; 1809 SNES_VI *vi = (SNES_VI*)snes->data; 1810 PetscBool changed_w = PETSC_FALSE,changed_y = PETSC_FALSE; 1811 1812 PetscFunctionBegin; 1813 ierr = PetscLogEventBegin(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1814 *flag = PETSC_TRUE; 1815 1816 ierr = VecNorm(y,NORM_2,ynorm);CHKERRQ(ierr); 1817 if (*ynorm == 0.0) { 1818 if (vi->lsmonitor) { 1819 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor,"Line search: Direction and size is 0\n");CHKERRQ(ierr); 1820 } 1821 *gnorm = fnorm; 1822 ierr = VecCopy(x,w);CHKERRQ(ierr); 1823 ierr = VecCopy(f,g);CHKERRQ(ierr); 1824 *flag = PETSC_FALSE; 1825 goto theend2; 1826 } 1827 if (*ynorm > vi->maxstep) { /* Step too big, so scale back */ 1828 ierr = VecScale(y,vi->maxstep/(*ynorm));CHKERRQ(ierr); 1829 *ynorm = vi->maxstep; 1830 } 1831 ierr = VecMaxPointwiseDivide(y,x,&rellength);CHKERRQ(ierr); 1832 minlambda = vi->minlambda/rellength; 1833 ierr = MatMult(snes->jacobian,y,w);CHKERRQ(ierr); 1834 #if defined(PETSC_USE_COMPLEX) 1835 ierr = VecDot(f,w,&cinitslope);CHKERRQ(ierr); 1836 initslope = PetscRealPart(cinitslope); 1837 #else 1838 ierr = VecDot(f,w,&initslope);CHKERRQ(ierr); 1839 #endif 1840 if (initslope > 0.0) initslope = -initslope; 1841 if (initslope == 0.0) initslope = -1.0; 1842 ierr = PetscInfo1(snes,"Initslope %G \n",initslope);CHKERRQ(ierr); 1843 1844 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); 1845 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1846 if (snes->nfuncs >= snes->max_funcs) { 1847 ierr = PetscInfo(snes,"Exceeded maximum function evaluations, while checking full step length!\n");CHKERRQ(ierr); 1848 *flag = PETSC_FALSE; 1849 snes->reason = SNES_DIVERGED_FUNCTION_COUNT; 1850 goto theend2; 1851 } 1852 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1853 if (snes->ops->solve != SNESSolveVI_SS) { 1854 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1855 } else { 1856 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1857 } 1858 if (snes->domainerror) { 1859 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1860 PetscFunctionReturn(0); 1861 } 1862 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1863 if (.5*(*gnorm)*(*gnorm) <= .5*fnorm*fnorm + vi->alpha*initslope) { /* Sufficient reduction */ 1864 if (vi->lsmonitor) { 1865 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line search: Using full step: fnorm %G gnorm %G\n",fnorm,*gnorm);CHKERRQ(ierr); 1866 } 1867 goto theend2; 1868 } 1869 1870 /* Fit points with quadratic */ 1871 lambda = 1.0; 1872 count = 1; 1873 while (PETSC_TRUE) { 1874 if (lambda <= minlambda) { /* bad luck; use full step */ 1875 if (vi->lsmonitor) { 1876 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor,"Line search: Unable to find good step length! %D \n",count);CHKERRQ(ierr); 1877 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); 1878 } 1879 ierr = VecCopy(x,w);CHKERRQ(ierr); 1880 *flag = PETSC_FALSE; 1881 break; 1882 } 1883 lambdatemp = -initslope/((*gnorm)*(*gnorm) - fnorm*fnorm - 2.0*initslope); 1884 if (lambdatemp > .5*lambda) lambdatemp = .5*lambda; 1885 if (lambdatemp <= .1*lambda) lambda = .1*lambda; 1886 else lambda = lambdatemp; 1887 1888 ierr = VecWAXPY(w,-lambda,y,x);CHKERRQ(ierr); 1889 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1890 if (snes->nfuncs >= snes->max_funcs) { 1891 ierr = PetscInfo1(snes,"Exceeded maximum function evaluations, while looking for good step length! %D \n",count);CHKERRQ(ierr); 1892 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); 1893 *flag = PETSC_FALSE; 1894 snes->reason = SNES_DIVERGED_FUNCTION_COUNT; 1895 break; 1896 } 1897 ierr = SNESComputeFunction(snes,w,g);CHKERRQ(ierr); 1898 if (snes->domainerror) { 1899 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1900 PetscFunctionReturn(0); 1901 } 1902 if (snes->ops->solve != SNESSolveVI_SS) { 1903 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1904 } else { 1905 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1906 } 1907 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1908 if (.5*(*gnorm)*(*gnorm) < .5*fnorm*fnorm + lambda*vi->alpha*initslope) { /* sufficient reduction */ 1909 if (vi->lsmonitor) { 1910 ierr = PetscViewerASCIIMonitorPrintf(vi->lsmonitor," Line Search: Quadratically determined step, lambda=%G\n",lambda);CHKERRQ(ierr); 1911 } 1912 break; 1913 } 1914 count++; 1915 } 1916 theend2: 1917 /* Optional user-defined check for line search step validity */ 1918 if (vi->postcheckstep) { 1919 ierr = (*vi->postcheckstep)(snes,x,y,w,vi->postcheck,&changed_y,&changed_w);CHKERRQ(ierr); 1920 if (changed_y) { 1921 ierr = VecWAXPY(w,-1.0,y,x);CHKERRQ(ierr); 1922 ierr = SNESVIProjectOntoBounds(snes,w);CHKERRQ(ierr); 1923 } 1924 if (changed_y || changed_w) { /* recompute the function if the step has changed */ 1925 ierr = SNESComputeFunction(snes,w,g); 1926 if (snes->domainerror) { 1927 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1928 PetscFunctionReturn(0); 1929 } 1930 if (snes->ops->solve != SNESSolveVI_SS) { 1931 ierr = SNESVIComputeInactiveSetFnorm(snes,g,w,gnorm);CHKERRQ(ierr); 1932 } else { 1933 ierr = VecNorm(g,NORM_2,gnorm);CHKERRQ(ierr); 1934 } 1935 1936 ierr = VecNormBegin(y,NORM_2,ynorm);CHKERRQ(ierr); 1937 ierr = VecNormEnd(y,NORM_2,ynorm);CHKERRQ(ierr); 1938 if (PetscIsInfOrNanReal(*gnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); 1939 } 1940 } 1941 ierr = PetscLogEventEnd(SNES_LineSearch,snes,x,f,g);CHKERRQ(ierr); 1942 PetscFunctionReturn(0); 1943 } 1944 1945 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*/ 1946 /* -------------------------------------------------------------------------- */ 1947 EXTERN_C_BEGIN 1948 #undef __FUNCT__ 1949 #define __FUNCT__ "SNESLineSearchSet_VI" 1950 PetscErrorCode SNESLineSearchSet_VI(SNES snes,FCN2 func,void *lsctx) 1951 { 1952 PetscFunctionBegin; 1953 ((SNES_VI *)(snes->data))->LineSearch = func; 1954 ((SNES_VI *)(snes->data))->lsP = lsctx; 1955 PetscFunctionReturn(0); 1956 } 1957 EXTERN_C_END 1958 1959 /* -------------------------------------------------------------------------- */ 1960 EXTERN_C_BEGIN 1961 #undef __FUNCT__ 1962 #define __FUNCT__ "SNESLineSearchSetMonitor_VI" 1963 PetscErrorCode SNESLineSearchSetMonitor_VI(SNES snes,PetscBool flg) 1964 { 1965 SNES_VI *vi = (SNES_VI*)snes->data; 1966 PetscErrorCode ierr; 1967 1968 PetscFunctionBegin; 1969 if (flg && !vi->lsmonitor) { 1970 ierr = PetscViewerASCIIMonitorCreate(((PetscObject)snes)->comm,"stdout",((PetscObject)snes)->tablevel,&vi->lsmonitor);CHKERRQ(ierr); 1971 } else if (!flg && vi->lsmonitor) { 1972 ierr = PetscViewerASCIIMonitorDestroy(&vi->lsmonitor);CHKERRQ(ierr); 1973 } 1974 PetscFunctionReturn(0); 1975 } 1976 EXTERN_C_END 1977 1978 /* 1979 SNESView_VI - Prints info from the SNESVI data structure. 1980 1981 Input Parameters: 1982 . SNES - the SNES context 1983 . viewer - visualization context 1984 1985 Application Interface Routine: SNESView() 1986 */ 1987 #undef __FUNCT__ 1988 #define __FUNCT__ "SNESView_VI" 1989 static PetscErrorCode SNESView_VI(SNES snes,PetscViewer viewer) 1990 { 1991 SNES_VI *vi = (SNES_VI *)snes->data; 1992 const char *cstr,*tstr; 1993 PetscErrorCode ierr; 1994 PetscBool iascii; 1995 1996 PetscFunctionBegin; 1997 ierr = PetscTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr); 1998 if (iascii) { 1999 if (vi->LineSearch == SNESLineSearchNo_VI) cstr = "SNESLineSearchNo"; 2000 else if (vi->LineSearch == SNESLineSearchQuadratic_VI) cstr = "SNESLineSearchQuadratic"; 2001 else if (vi->LineSearch == SNESLineSearchCubic_VI) cstr = "SNESLineSearchCubic"; 2002 else cstr = "unknown"; 2003 if (snes->ops->solve == SNESSolveVI_SS) tstr = "Semismooth"; 2004 else if (snes->ops->solve == SNESSolveVI_RS) tstr = "Reduced Space"; 2005 else if (snes->ops->solve == SNESSolveVI_RS2) tstr = "Augmented Space"; 2006 else tstr = "unknown"; 2007 ierr = PetscViewerASCIIPrintf(viewer," VI algorithm: %s\n",tstr);CHKERRQ(ierr); 2008 ierr = PetscViewerASCIIPrintf(viewer," line search variant: %s\n",cstr);CHKERRQ(ierr); 2009 ierr = PetscViewerASCIIPrintf(viewer," alpha=%G, maxstep=%G, minlambda=%G\n",vi->alpha,vi->maxstep,vi->minlambda);CHKERRQ(ierr); 2010 } else { 2011 SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Viewer type %s not supported for SNES EQ VI",((PetscObject)viewer)->type_name); 2012 } 2013 PetscFunctionReturn(0); 2014 } 2015 2016 #undef __FUNCT__ 2017 #define __FUNCT__ "SNESVISetVariableBounds" 2018 /*@ 2019 SNESVISetVariableBounds - Sets the lower and upper bounds for the solution vector. xl <= x <= xu. 2020 2021 Input Parameters: 2022 . snes - the SNES context. 2023 . xl - lower bound. 2024 . xu - upper bound. 2025 2026 Notes: 2027 If this routine is not called then the lower and upper bounds are set to 2028 SNES_VI_INF and SNES_VI_NINF respectively during SNESSetUp(). 2029 2030 @*/ 2031 PetscErrorCode SNESVISetVariableBounds(SNES snes, Vec xl, Vec xu) 2032 { 2033 SNES_VI *vi; 2034 PetscErrorCode ierr; 2035 2036 PetscFunctionBegin; 2037 PetscValidHeaderSpecific(snes,SNES_CLASSID,1); 2038 PetscValidHeaderSpecific(xl,VEC_CLASSID,2); 2039 PetscValidHeaderSpecific(xu,VEC_CLASSID,3); 2040 if (!snes->vec_func) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Must call SNESSetFunction() first"); 2041 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); 2042 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); 2043 ierr = SNESSetType(snes,SNESVI);CHKERRQ(ierr); 2044 vi = (SNES_VI*)snes->data; 2045 vi->usersetxbounds = PETSC_TRUE; 2046 vi->xl = xl; 2047 vi->xu = xu; 2048 PetscFunctionReturn(0); 2049 } 2050 2051 /* -------------------------------------------------------------------------- */ 2052 /* 2053 SNESSetFromOptions_VI - Sets various parameters for the SNESVI method. 2054 2055 Input Parameter: 2056 . snes - the SNES context 2057 2058 Application Interface Routine: SNESSetFromOptions() 2059 */ 2060 #undef __FUNCT__ 2061 #define __FUNCT__ "SNESSetFromOptions_VI" 2062 static PetscErrorCode SNESSetFromOptions_VI(SNES snes) 2063 { 2064 SNES_VI *vi = (SNES_VI *)snes->data; 2065 const char *lses[] = {"basic","basicnonorms","quadratic","cubic"}; 2066 const char *vies[] = {"ss","rs","rs2"}; 2067 PetscErrorCode ierr; 2068 PetscInt indx; 2069 PetscBool flg,set,flg2; 2070 2071 PetscFunctionBegin; 2072 ierr = PetscOptionsHead("SNES semismooth method options");CHKERRQ(ierr); 2073 ierr = PetscOptionsBool("-snes_vi_monitor","Monitor all non-active variables","None",PETSC_FALSE,&flg,0);CHKERRQ(ierr); 2074 if (flg) { 2075 ierr = SNESMonitorSet(snes,SNESMonitorVI,0,0);CHKERRQ(ierr); 2076 } 2077 ierr = PetscOptionsReal("-snes_ls_alpha","Function norm must decrease by","None",vi->alpha,&vi->alpha,0);CHKERRQ(ierr); 2078 ierr = PetscOptionsReal("-snes_ls_maxstep","Step must be less than","None",vi->maxstep,&vi->maxstep,0);CHKERRQ(ierr); 2079 ierr = PetscOptionsReal("-snes_ls_minlambda","Minimum lambda allowed","None",vi->minlambda,&vi->minlambda,0);CHKERRQ(ierr); 2080 ierr = PetscOptionsReal("-snes_vi_const_tol","constraint tolerance","None",vi->const_tol,&vi->const_tol,0);CHKERRQ(ierr); 2081 ierr = PetscOptionsBool("-snes_ls_monitor","Print progress of line searches","SNESLineSearchSetMonitor",vi->lsmonitor ? PETSC_TRUE : PETSC_FALSE,&flg,&set);CHKERRQ(ierr); 2082 if (set) {ierr = SNESLineSearchSetMonitor(snes,flg);CHKERRQ(ierr);} 2083 ierr = PetscOptionsEList("-snes_vi_type","Semismooth algorithm used","",vies,3,"ss",&indx,&flg2);CHKERRQ(ierr); 2084 if (flg2) { 2085 switch (indx) { 2086 case 0: 2087 snes->ops->solve = SNESSolveVI_SS; 2088 break; 2089 case 1: 2090 snes->ops->solve = SNESSolveVI_RS; 2091 break; 2092 case 2: 2093 snes->ops->solve = SNESSolveVI_RS2; 2094 } 2095 } 2096 ierr = PetscOptionsEList("-snes_ls","Line search used","SNESLineSearchSet",lses,4,"basic",&indx,&flg);CHKERRQ(ierr); 2097 if (flg) { 2098 switch (indx) { 2099 case 0: 2100 ierr = SNESLineSearchSet(snes,SNESLineSearchNo_VI,PETSC_NULL);CHKERRQ(ierr); 2101 break; 2102 case 1: 2103 ierr = SNESLineSearchSet(snes,SNESLineSearchNoNorms_VI,PETSC_NULL);CHKERRQ(ierr); 2104 break; 2105 case 2: 2106 ierr = SNESLineSearchSet(snes,SNESLineSearchQuadratic_VI,PETSC_NULL);CHKERRQ(ierr); 2107 break; 2108 case 3: 2109 ierr = SNESLineSearchSet(snes,SNESLineSearchCubic_VI,PETSC_NULL);CHKERRQ(ierr); 2110 break; 2111 } 2112 } 2113 ierr = PetscOptionsTail();CHKERRQ(ierr); 2114 PetscFunctionReturn(0); 2115 } 2116 /* -------------------------------------------------------------------------- */ 2117 /*MC 2118 SNESVI - Semismooth newton method based nonlinear solver that uses a line search 2119 2120 Options Database: 2121 + -snes_ls [cubic,quadratic,basic,basicnonorms] - Selects line search 2122 . -snes_ls_alpha <alpha> - Sets alpha 2123 . -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) 2124 . -snes_ls_minlambda <minlambda> - Sets the minimum lambda the line search will use minlambda / max_i ( y[i]/x[i] ) 2125 - -snes_ls_monitor - print information about progress of line searches 2126 2127 2128 Level: beginner 2129 2130 .seealso: SNESCreate(), SNES, SNESSetType(), SNESTR, SNESLineSearchSet(), 2131 SNESLineSearchSetPostCheck(), SNESLineSearchNo(), SNESLineSearchCubic(), SNESLineSearchQuadratic(), 2132 SNESLineSearchSet(), SNESLineSearchNoNorms(), SNESLineSearchSetPreCheck(), SNESLineSearchSetParams(), SNESLineSearchGetParams() 2133 2134 M*/ 2135 EXTERN_C_BEGIN 2136 #undef __FUNCT__ 2137 #define __FUNCT__ "SNESCreate_VI" 2138 PetscErrorCode SNESCreate_VI(SNES snes) 2139 { 2140 PetscErrorCode ierr; 2141 SNES_VI *vi; 2142 2143 PetscFunctionBegin; 2144 snes->ops->setup = SNESSetUp_VI; 2145 snes->ops->solve = SNESSolveVI_RS; 2146 snes->ops->destroy = SNESDestroy_VI; 2147 snes->ops->setfromoptions = SNESSetFromOptions_VI; 2148 snes->ops->view = SNESView_VI; 2149 snes->ops->reset = 0; /* XXX Implement!!! */ 2150 snes->ops->converged = SNESDefaultConverged_VI; 2151 2152 ierr = PetscNewLog(snes,SNES_VI,&vi);CHKERRQ(ierr); 2153 snes->data = (void*)vi; 2154 vi->alpha = 1.e-4; 2155 vi->maxstep = 1.e8; 2156 vi->minlambda = 1.e-12; 2157 vi->LineSearch = SNESLineSearchNo_VI; 2158 vi->lsP = PETSC_NULL; 2159 vi->postcheckstep = PETSC_NULL; 2160 vi->postcheck = PETSC_NULL; 2161 vi->precheckstep = PETSC_NULL; 2162 vi->precheck = PETSC_NULL; 2163 vi->const_tol = 2.2204460492503131e-16; 2164 vi->checkredundancy = PETSC_NULL; 2165 2166 ierr = PetscObjectComposeFunctionDynamic((PetscObject)snes,"SNESLineSearchSetMonitor_C","SNESLineSearchSetMonitor_VI",SNESLineSearchSetMonitor_VI);CHKERRQ(ierr); 2167 ierr = PetscObjectComposeFunctionDynamic((PetscObject)snes,"SNESLineSearchSet_C","SNESLineSearchSet_VI",SNESLineSearchSet_VI);CHKERRQ(ierr); 2168 2169 PetscFunctionReturn(0); 2170 } 2171 EXTERN_C_END 2172