1b79b07cfSJed Brown 2b45d2f2cSJed Brown #include <petsc-private/snesimpl.h> 3b79b07cfSJed Brown 4b79b07cfSJed Brown #undef __FUNCT__ 5b79b07cfSJed Brown #define __FUNCT__ "SNESSolve_KSPONLY" 6b79b07cfSJed Brown static PetscErrorCode SNESSolve_KSPONLY(SNES snes) 7b79b07cfSJed Brown { 8b79b07cfSJed Brown PetscErrorCode ierr; 9b79b07cfSJed Brown PetscInt lits; 10b79b07cfSJed Brown MatStructure flg = DIFFERENT_NONZERO_PATTERN; 11b79b07cfSJed Brown Vec Y,X,F; 12b79b07cfSJed Brown KSPConvergedReason kspreason; 13b79b07cfSJed Brown 14b79b07cfSJed Brown PetscFunctionBegin; 15b79b07cfSJed Brown snes->numFailures = 0; 16b79b07cfSJed Brown snes->numLinearSolveFailures = 0; 17b79b07cfSJed Brown snes->reason = SNES_CONVERGED_ITERATING; 18b79b07cfSJed Brown snes->iter = 0; 19b79b07cfSJed Brown snes->norm = 0.0; 20b79b07cfSJed Brown 21b79b07cfSJed Brown X = snes->vec_sol; 22b79b07cfSJed Brown F = snes->vec_func; 23b79b07cfSJed Brown Y = snes->vec_sol_update; 24b79b07cfSJed Brown 25b79b07cfSJed Brown ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); 26b79b07cfSJed Brown if (snes->domainerror) { 27b79b07cfSJed Brown snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; 28b79b07cfSJed Brown PetscFunctionReturn(0); 29b79b07cfSJed Brown } 30a5eaddd9SBarry Smith if (snes->numbermonitors) { 31a5eaddd9SBarry Smith PetscReal fnorm; 32a5eaddd9SBarry Smith ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); 33a5eaddd9SBarry Smith ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr); 34a5eaddd9SBarry Smith } 35b79b07cfSJed Brown 365341784dSBarry Smith /* Call general purpose update function */ 375341784dSBarry Smith if (snes->ops->update) { 385341784dSBarry Smith ierr = (*snes->ops->update)(snes, 0);CHKERRQ(ierr); 395341784dSBarry Smith } 405341784dSBarry Smith 41b79b07cfSJed Brown /* Solve J Y = F, where J is Jacobian matrix */ 42b79b07cfSJed Brown ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr); 43b79b07cfSJed Brown ierr = KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre,flg);CHKERRQ(ierr); 44b79b07cfSJed Brown ierr = KSPSolve(snes->ksp,F,Y);CHKERRQ(ierr); 45b79b07cfSJed Brown ierr = KSPGetConvergedReason(snes->ksp,&kspreason);CHKERRQ(ierr); 46b79b07cfSJed Brown if (kspreason < 0 && ++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) { 47b79b07cfSJed Brown ierr = PetscInfo2(snes,"iter=%D, number linear solve failures %D greater than current SNES allowed, stopping solve\n",snes->iter,snes->numLinearSolveFailures);CHKERRQ(ierr); 48b79b07cfSJed Brown snes->reason = SNES_DIVERGED_LINEAR_SOLVE; 491aa26658SKarl Rupp } else snes->reason = SNES_CONVERGED_ITS; 501aa26658SKarl Rupp 51b79b07cfSJed Brown ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr); 52b79b07cfSJed Brown snes->linear_its += lits; 53b79b07cfSJed Brown ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr); 54b79b07cfSJed Brown snes->iter++; 55b79b07cfSJed Brown 56b79b07cfSJed Brown /* Take the computed step. */ 57b79b07cfSJed Brown ierr = VecAXPY(X,-1.0,Y);CHKERRQ(ierr); 58a5eaddd9SBarry Smith if (snes->numbermonitors) { 59a5eaddd9SBarry Smith PetscReal fnorm; 60a5eaddd9SBarry Smith ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); 61a5eaddd9SBarry Smith ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); 62a5eaddd9SBarry Smith ierr = SNESMonitor(snes,1,fnorm);CHKERRQ(ierr); 63a5eaddd9SBarry Smith } 64b79b07cfSJed Brown PetscFunctionReturn(0); 65b79b07cfSJed Brown } 66b79b07cfSJed Brown 67b79b07cfSJed Brown #undef __FUNCT__ 68b79b07cfSJed Brown #define __FUNCT__ "SNESSetUp_KSPONLY" 69b79b07cfSJed Brown static PetscErrorCode SNESSetUp_KSPONLY(SNES snes) 70b79b07cfSJed Brown { 716cab3a1bSJed Brown PetscErrorCode ierr; 72b79b07cfSJed Brown 73b79b07cfSJed Brown PetscFunctionBegin; 746cab3a1bSJed Brown ierr = SNESSetUpMatrices(snes);CHKERRQ(ierr); 75b79b07cfSJed Brown PetscFunctionReturn(0); 76b79b07cfSJed Brown } 77b79b07cfSJed Brown 78b79b07cfSJed Brown #undef __FUNCT__ 79b79b07cfSJed Brown #define __FUNCT__ "SNESDestroy_KSPONLY" 80b79b07cfSJed Brown static PetscErrorCode SNESDestroy_KSPONLY(SNES snes) 81b79b07cfSJed Brown { 82b79b07cfSJed Brown 83b79b07cfSJed Brown PetscFunctionBegin; 84b79b07cfSJed Brown PetscFunctionReturn(0); 85b79b07cfSJed Brown } 86b79b07cfSJed Brown 87b79b07cfSJed Brown /* -------------------------------------------------------------------------- */ 88b79b07cfSJed Brown /*MC 89b79b07cfSJed Brown SNESKSPONLY - Nonlinear solver that only performs one Newton step and does not compute any norms. 90b79b07cfSJed Brown The main purpose of this solver is to solve linear problems using the SNES interface, without 91b79b07cfSJed Brown any additional overhead in the form of vector operations. 92b79b07cfSJed Brown 93b79b07cfSJed Brown Level: beginner 94b79b07cfSJed Brown 9504d7464bSBarry Smith .seealso: SNESCreate(), SNES, SNESSetType(), SNESNEWTONLS, SNESNEWTONTR 96b79b07cfSJed Brown M*/ 97b79b07cfSJed Brown #undef __FUNCT__ 98b79b07cfSJed Brown #define __FUNCT__ "SNESCreate_KSPONLY" 99*8cc058d9SJed Brown PETSC_EXTERN PetscErrorCode SNESCreate_KSPONLY(SNES snes) 100b79b07cfSJed Brown { 101b79b07cfSJed Brown 102b79b07cfSJed Brown PetscFunctionBegin; 103b79b07cfSJed Brown snes->ops->setup = SNESSetUp_KSPONLY; 104b79b07cfSJed Brown snes->ops->solve = SNESSolve_KSPONLY; 105b79b07cfSJed Brown snes->ops->destroy = SNESDestroy_KSPONLY; 10637596af1SLisandro Dalcin snes->ops->setfromoptions = 0; 10737596af1SLisandro Dalcin snes->ops->view = 0; 10837596af1SLisandro Dalcin snes->ops->reset = 0; 109b79b07cfSJed Brown 11042f4f86dSBarry Smith snes->usesksp = PETSC_TRUE; 11142f4f86dSBarry Smith snes->usespc = PETSC_FALSE; 11242f4f86dSBarry Smith 113b79b07cfSJed Brown snes->data = 0; 114b79b07cfSJed Brown PetscFunctionReturn(0); 115b79b07cfSJed Brown } 116