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 */ 4294ab13aaSBarry Smith ierr = SNESComputeJacobian(snes,X,snes->jacobian,snes->jacobian_pre,&flg);CHKERRQ(ierr); 43*23ee1639SBarry Smith if (flg == SAME_PRECONDITIONER) {ierr = KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);CHKERRQ(ierr);} 44*23ee1639SBarry Smith else {ierr = KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);CHKERRQ(ierr);} 45*23ee1639SBarry Smith ierr = KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre);CHKERRQ(ierr); 46b79b07cfSJed Brown ierr = KSPSolve(snes->ksp,F,Y);CHKERRQ(ierr); 47b79b07cfSJed Brown ierr = KSPGetConvergedReason(snes->ksp,&kspreason);CHKERRQ(ierr); 48b79b07cfSJed Brown if (kspreason < 0 && ++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) { 49b79b07cfSJed 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); 50b79b07cfSJed Brown snes->reason = SNES_DIVERGED_LINEAR_SOLVE; 511aa26658SKarl Rupp } else snes->reason = SNES_CONVERGED_ITS; 521aa26658SKarl Rupp 53b79b07cfSJed Brown ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr); 54b79b07cfSJed Brown snes->linear_its += lits; 55b79b07cfSJed Brown ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr); 56b79b07cfSJed Brown snes->iter++; 57b79b07cfSJed Brown 58b79b07cfSJed Brown /* Take the computed step. */ 59b79b07cfSJed Brown ierr = VecAXPY(X,-1.0,Y);CHKERRQ(ierr); 60a5eaddd9SBarry Smith if (snes->numbermonitors) { 61a5eaddd9SBarry Smith PetscReal fnorm; 62a5eaddd9SBarry Smith ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); 63a5eaddd9SBarry Smith ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); 64a5eaddd9SBarry Smith ierr = SNESMonitor(snes,1,fnorm);CHKERRQ(ierr); 65a5eaddd9SBarry Smith } 66b79b07cfSJed Brown PetscFunctionReturn(0); 67b79b07cfSJed Brown } 68b79b07cfSJed Brown 69b79b07cfSJed Brown #undef __FUNCT__ 70b79b07cfSJed Brown #define __FUNCT__ "SNESSetUp_KSPONLY" 71b79b07cfSJed Brown static PetscErrorCode SNESSetUp_KSPONLY(SNES snes) 72b79b07cfSJed Brown { 736cab3a1bSJed Brown PetscErrorCode ierr; 74b79b07cfSJed Brown 75b79b07cfSJed Brown PetscFunctionBegin; 766cab3a1bSJed Brown ierr = SNESSetUpMatrices(snes);CHKERRQ(ierr); 77b79b07cfSJed Brown PetscFunctionReturn(0); 78b79b07cfSJed Brown } 79b79b07cfSJed Brown 80b79b07cfSJed Brown #undef __FUNCT__ 81b79b07cfSJed Brown #define __FUNCT__ "SNESDestroy_KSPONLY" 82b79b07cfSJed Brown static PetscErrorCode SNESDestroy_KSPONLY(SNES snes) 83b79b07cfSJed Brown { 84b79b07cfSJed Brown 85b79b07cfSJed Brown PetscFunctionBegin; 86b79b07cfSJed Brown PetscFunctionReturn(0); 87b79b07cfSJed Brown } 88b79b07cfSJed Brown 89b79b07cfSJed Brown /* -------------------------------------------------------------------------- */ 90b79b07cfSJed Brown /*MC 91b79b07cfSJed Brown SNESKSPONLY - Nonlinear solver that only performs one Newton step and does not compute any norms. 92b79b07cfSJed Brown The main purpose of this solver is to solve linear problems using the SNES interface, without 93b79b07cfSJed Brown any additional overhead in the form of vector operations. 94b79b07cfSJed Brown 95b79b07cfSJed Brown Level: beginner 96b79b07cfSJed Brown 9704d7464bSBarry Smith .seealso: SNESCreate(), SNES, SNESSetType(), SNESNEWTONLS, SNESNEWTONTR 98b79b07cfSJed Brown M*/ 99b79b07cfSJed Brown #undef __FUNCT__ 100b79b07cfSJed Brown #define __FUNCT__ "SNESCreate_KSPONLY" 1018cc058d9SJed Brown PETSC_EXTERN PetscErrorCode SNESCreate_KSPONLY(SNES snes) 102b79b07cfSJed Brown { 103b79b07cfSJed Brown 104b79b07cfSJed Brown PetscFunctionBegin; 105b79b07cfSJed Brown snes->ops->setup = SNESSetUp_KSPONLY; 106b79b07cfSJed Brown snes->ops->solve = SNESSolve_KSPONLY; 107b79b07cfSJed Brown snes->ops->destroy = SNESDestroy_KSPONLY; 10837596af1SLisandro Dalcin snes->ops->setfromoptions = 0; 10937596af1SLisandro Dalcin snes->ops->view = 0; 11037596af1SLisandro Dalcin snes->ops->reset = 0; 111b79b07cfSJed Brown 11242f4f86dSBarry Smith snes->usesksp = PETSC_TRUE; 11342f4f86dSBarry Smith snes->usespc = PETSC_FALSE; 11442f4f86dSBarry Smith 115b79b07cfSJed Brown snes->data = 0; 116b79b07cfSJed Brown PetscFunctionReturn(0); 117b79b07cfSJed Brown } 118