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 Vec Y,X,F; 11b79b07cfSJed Brown KSPConvergedReason kspreason; 12b79b07cfSJed Brown 13b79b07cfSJed Brown PetscFunctionBegin; 14b79b07cfSJed Brown snes->numFailures = 0; 15b79b07cfSJed Brown snes->numLinearSolveFailures = 0; 16b79b07cfSJed Brown snes->reason = SNES_CONVERGED_ITERATING; 17b79b07cfSJed Brown snes->iter = 0; 18b79b07cfSJed Brown snes->norm = 0.0; 19b79b07cfSJed Brown 20b79b07cfSJed Brown X = snes->vec_sol; 21b79b07cfSJed Brown F = snes->vec_func; 22b79b07cfSJed Brown Y = snes->vec_sol_update; 23b79b07cfSJed Brown 24b79b07cfSJed Brown ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); 25b79b07cfSJed Brown if (snes->domainerror) { 26b79b07cfSJed Brown snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; 27b79b07cfSJed Brown PetscFunctionReturn(0); 28b79b07cfSJed Brown } 29a5eaddd9SBarry Smith if (snes->numbermonitors) { 30a5eaddd9SBarry Smith PetscReal fnorm; 31a5eaddd9SBarry Smith ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); 32a5eaddd9SBarry Smith ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr); 33a5eaddd9SBarry Smith } 34b79b07cfSJed Brown 355341784dSBarry Smith /* Call general purpose update function */ 365341784dSBarry Smith if (snes->ops->update) { 375341784dSBarry Smith ierr = (*snes->ops->update)(snes, 0);CHKERRQ(ierr); 385341784dSBarry Smith } 395341784dSBarry Smith 40b79b07cfSJed Brown /* Solve J Y = F, where J is Jacobian matrix */ 41*d1e9a80fSBarry Smith ierr = SNESComputeJacobian(snes,X,snes->jacobian,snes->jacobian_pre);CHKERRQ(ierr); 4223ee1639SBarry Smith ierr = KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre);CHKERRQ(ierr); 43b79b07cfSJed Brown ierr = KSPSolve(snes->ksp,F,Y);CHKERRQ(ierr); 44b79b07cfSJed Brown ierr = KSPGetConvergedReason(snes->ksp,&kspreason);CHKERRQ(ierr); 45b79b07cfSJed Brown if (kspreason < 0 && ++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) { 46b79b07cfSJed 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); 47b79b07cfSJed Brown snes->reason = SNES_DIVERGED_LINEAR_SOLVE; 481aa26658SKarl Rupp } else snes->reason = SNES_CONVERGED_ITS; 491aa26658SKarl Rupp 50b79b07cfSJed Brown ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr); 51b79b07cfSJed Brown snes->linear_its += lits; 52b79b07cfSJed Brown ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr); 53b79b07cfSJed Brown snes->iter++; 54b79b07cfSJed Brown 55b79b07cfSJed Brown /* Take the computed step. */ 56b79b07cfSJed Brown ierr = VecAXPY(X,-1.0,Y);CHKERRQ(ierr); 57a5eaddd9SBarry Smith if (snes->numbermonitors) { 58a5eaddd9SBarry Smith PetscReal fnorm; 59a5eaddd9SBarry Smith ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); 60a5eaddd9SBarry Smith ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); 61a5eaddd9SBarry Smith ierr = SNESMonitor(snes,1,fnorm);CHKERRQ(ierr); 62a5eaddd9SBarry Smith } 63b79b07cfSJed Brown PetscFunctionReturn(0); 64b79b07cfSJed Brown } 65b79b07cfSJed Brown 66b79b07cfSJed Brown #undef __FUNCT__ 67b79b07cfSJed Brown #define __FUNCT__ "SNESSetUp_KSPONLY" 68b79b07cfSJed Brown static PetscErrorCode SNESSetUp_KSPONLY(SNES snes) 69b79b07cfSJed Brown { 706cab3a1bSJed Brown PetscErrorCode ierr; 71b79b07cfSJed Brown 72b79b07cfSJed Brown PetscFunctionBegin; 736cab3a1bSJed Brown ierr = SNESSetUpMatrices(snes);CHKERRQ(ierr); 74b79b07cfSJed Brown PetscFunctionReturn(0); 75b79b07cfSJed Brown } 76b79b07cfSJed Brown 77b79b07cfSJed Brown #undef __FUNCT__ 78b79b07cfSJed Brown #define __FUNCT__ "SNESDestroy_KSPONLY" 79b79b07cfSJed Brown static PetscErrorCode SNESDestroy_KSPONLY(SNES snes) 80b79b07cfSJed Brown { 81b79b07cfSJed Brown 82b79b07cfSJed Brown PetscFunctionBegin; 83b79b07cfSJed Brown PetscFunctionReturn(0); 84b79b07cfSJed Brown } 85b79b07cfSJed Brown 86b79b07cfSJed Brown /* -------------------------------------------------------------------------- */ 87b79b07cfSJed Brown /*MC 88b79b07cfSJed Brown SNESKSPONLY - Nonlinear solver that only performs one Newton step and does not compute any norms. 89b79b07cfSJed Brown The main purpose of this solver is to solve linear problems using the SNES interface, without 90b79b07cfSJed Brown any additional overhead in the form of vector operations. 91b79b07cfSJed Brown 92b79b07cfSJed Brown Level: beginner 93b79b07cfSJed Brown 9404d7464bSBarry Smith .seealso: SNESCreate(), SNES, SNESSetType(), SNESNEWTONLS, SNESNEWTONTR 95b79b07cfSJed Brown M*/ 96b79b07cfSJed Brown #undef __FUNCT__ 97b79b07cfSJed Brown #define __FUNCT__ "SNESCreate_KSPONLY" 988cc058d9SJed Brown PETSC_EXTERN PetscErrorCode SNESCreate_KSPONLY(SNES snes) 99b79b07cfSJed Brown { 100b79b07cfSJed Brown 101b79b07cfSJed Brown PetscFunctionBegin; 102b79b07cfSJed Brown snes->ops->setup = SNESSetUp_KSPONLY; 103b79b07cfSJed Brown snes->ops->solve = SNESSolve_KSPONLY; 104b79b07cfSJed Brown snes->ops->destroy = SNESDestroy_KSPONLY; 10537596af1SLisandro Dalcin snes->ops->setfromoptions = 0; 10637596af1SLisandro Dalcin snes->ops->view = 0; 10737596af1SLisandro Dalcin snes->ops->reset = 0; 108b79b07cfSJed Brown 10942f4f86dSBarry Smith snes->usesksp = PETSC_TRUE; 11042f4f86dSBarry Smith snes->usespc = PETSC_FALSE; 11142f4f86dSBarry Smith 112b79b07cfSJed Brown snes->data = 0; 113b79b07cfSJed Brown PetscFunctionReturn(0); 114b79b07cfSJed Brown } 115