1b79b07cfSJed Brown 2af0996ceSBarry Smith #include <petsc/private/snesimpl.h> 3b79b07cfSJed Brown 4b79b07cfSJed Brown static PetscErrorCode SNESSolve_KSPONLY(SNES snes) 5b79b07cfSJed Brown { 6b79b07cfSJed Brown PetscErrorCode ierr; 7b79b07cfSJed Brown PetscInt lits; 8b79b07cfSJed Brown Vec Y,X,F; 9b79b07cfSJed Brown 10b79b07cfSJed Brown PetscFunctionBegin; 116c4ed002SBarry Smith if (snes->xl || snes->xu || snes->ops->computevariablebounds) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONGSTATE, "SNES solver %s does not support bounds", ((PetscObject)snes)->type_name); 12c579b300SPatrick Farrell 13b79b07cfSJed Brown snes->numFailures = 0; 14b79b07cfSJed Brown snes->numLinearSolveFailures = 0; 15b79b07cfSJed Brown snes->reason = SNES_CONVERGED_ITERATING; 16b79b07cfSJed Brown snes->iter = 0; 17b79b07cfSJed Brown snes->norm = 0.0; 18b79b07cfSJed Brown 19b79b07cfSJed Brown X = snes->vec_sol; 20b79b07cfSJed Brown F = snes->vec_func; 21b79b07cfSJed Brown Y = snes->vec_sol_update; 22b79b07cfSJed Brown 23b79b07cfSJed Brown ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); 24a5eaddd9SBarry Smith if (snes->numbermonitors) { 25a5eaddd9SBarry Smith PetscReal fnorm; 26a5eaddd9SBarry Smith ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); 27a5eaddd9SBarry Smith ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr); 28a5eaddd9SBarry Smith } 29b79b07cfSJed Brown 305341784dSBarry Smith /* Call general purpose update function */ 315341784dSBarry Smith if (snes->ops->update) { 325341784dSBarry Smith ierr = (*snes->ops->update)(snes, 0);CHKERRQ(ierr); 335341784dSBarry Smith } 345341784dSBarry Smith 35b79b07cfSJed Brown /* Solve J Y = F, where J is Jacobian matrix */ 36d1e9a80fSBarry Smith ierr = SNESComputeJacobian(snes,X,snes->jacobian,snes->jacobian_pre);CHKERRQ(ierr); 3723ee1639SBarry Smith ierr = KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre);CHKERRQ(ierr); 38b79b07cfSJed Brown ierr = KSPSolve(snes->ksp,F,Y);CHKERRQ(ierr); 39422a814eSBarry Smith snes->reason = SNES_CONVERGED_ITS; 40422a814eSBarry Smith SNESCheckKSPSolve(snes); 411aa26658SKarl Rupp 42b79b07cfSJed Brown ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr); 43b79b07cfSJed Brown snes->linear_its += lits; 44b79b07cfSJed Brown ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr); 45b79b07cfSJed Brown snes->iter++; 46b79b07cfSJed Brown 47b79b07cfSJed Brown /* Take the computed step. */ 48b79b07cfSJed Brown ierr = VecAXPY(X,-1.0,Y);CHKERRQ(ierr); 49a5eaddd9SBarry Smith if (snes->numbermonitors) { 50a5eaddd9SBarry Smith PetscReal fnorm; 51fef909d3SLawrence Mitchell ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); 52a5eaddd9SBarry Smith ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); 53a5eaddd9SBarry Smith ierr = SNESMonitor(snes,1,fnorm);CHKERRQ(ierr); 54a5eaddd9SBarry Smith } 55b79b07cfSJed Brown PetscFunctionReturn(0); 56b79b07cfSJed Brown } 57b79b07cfSJed Brown 58b79b07cfSJed Brown static PetscErrorCode SNESSetUp_KSPONLY(SNES snes) 59b79b07cfSJed Brown { 606cab3a1bSJed Brown PetscErrorCode ierr; 61b79b07cfSJed Brown 62b79b07cfSJed Brown PetscFunctionBegin; 636cab3a1bSJed Brown ierr = SNESSetUpMatrices(snes);CHKERRQ(ierr); 64b79b07cfSJed Brown PetscFunctionReturn(0); 65b79b07cfSJed Brown } 66b79b07cfSJed Brown 67b79b07cfSJed Brown static PetscErrorCode SNESDestroy_KSPONLY(SNES snes) 68b79b07cfSJed Brown { 69b79b07cfSJed Brown 70b79b07cfSJed Brown PetscFunctionBegin; 71b79b07cfSJed Brown PetscFunctionReturn(0); 72b79b07cfSJed Brown } 73b79b07cfSJed Brown 74b79b07cfSJed Brown /* -------------------------------------------------------------------------- */ 75b79b07cfSJed Brown /*MC 76b79b07cfSJed Brown SNESKSPONLY - Nonlinear solver that only performs one Newton step and does not compute any norms. 77b79b07cfSJed Brown The main purpose of this solver is to solve linear problems using the SNES interface, without 78b79b07cfSJed Brown any additional overhead in the form of vector operations. 79b79b07cfSJed Brown 80b79b07cfSJed Brown Level: beginner 81b79b07cfSJed Brown 8204d7464bSBarry Smith .seealso: SNESCreate(), SNES, SNESSetType(), SNESNEWTONLS, SNESNEWTONTR 83b79b07cfSJed Brown M*/ 848cc058d9SJed Brown PETSC_EXTERN PetscErrorCode SNESCreate_KSPONLY(SNES snes) 85b79b07cfSJed Brown { 86b79b07cfSJed Brown 87b79b07cfSJed Brown PetscFunctionBegin; 88b79b07cfSJed Brown snes->ops->setup = SNESSetUp_KSPONLY; 89b79b07cfSJed Brown snes->ops->solve = SNESSolve_KSPONLY; 90b79b07cfSJed Brown snes->ops->destroy = SNESDestroy_KSPONLY; 9137596af1SLisandro Dalcin snes->ops->setfromoptions = 0; 9237596af1SLisandro Dalcin snes->ops->view = 0; 9337596af1SLisandro Dalcin snes->ops->reset = 0; 94b79b07cfSJed Brown 9542f4f86dSBarry Smith snes->usesksp = PETSC_TRUE; 96*efd4aadfSBarry Smith snes->usesnpc = PETSC_FALSE; 9742f4f86dSBarry Smith 984fc747eaSLawrence Mitchell snes->alwayscomputesfinalresidual = PETSC_FALSE; 994fc747eaSLawrence Mitchell 100b79b07cfSJed Brown snes->data = 0; 101b79b07cfSJed Brown PetscFunctionReturn(0); 102b79b07cfSJed Brown } 103