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