1b79b07cfSJed Brown #define PETSCSNES_DLL 2b79b07cfSJed Brown 3b79b07cfSJed Brown #include "private/snesimpl.h" 4b79b07cfSJed Brown 5b79b07cfSJed Brown #undef __FUNCT__ 6b79b07cfSJed Brown #define __FUNCT__ "SNESSolve_KSPONLY" 7b79b07cfSJed Brown static PetscErrorCode SNESSolve_KSPONLY(SNES snes) 8b79b07cfSJed Brown { 9b79b07cfSJed Brown PetscErrorCode ierr; 10b79b07cfSJed Brown PetscInt lits; 11b79b07cfSJed Brown MatStructure flg = DIFFERENT_NONZERO_PATTERN; 12b79b07cfSJed Brown Vec Y,X,F; 13b79b07cfSJed Brown KSPConvergedReason kspreason; 14b79b07cfSJed Brown 15b79b07cfSJed Brown PetscFunctionBegin; 16b79b07cfSJed Brown snes->numFailures = 0; 17b79b07cfSJed Brown snes->numLinearSolveFailures = 0; 18b79b07cfSJed Brown snes->reason = SNES_CONVERGED_ITERATING; 19b79b07cfSJed Brown snes->iter = 0; 20b79b07cfSJed Brown snes->norm = 0.0; 21b79b07cfSJed Brown 22b79b07cfSJed Brown X = snes->vec_sol; 23b79b07cfSJed Brown F = snes->vec_func; 24b79b07cfSJed Brown Y = snes->vec_sol_update; 25b79b07cfSJed Brown 26b79b07cfSJed Brown ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); 27b79b07cfSJed Brown if (snes->domainerror) { 28b79b07cfSJed Brown snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; 29b79b07cfSJed Brown PetscFunctionReturn(0); 30b79b07cfSJed Brown } 31b79b07cfSJed Brown 32b79b07cfSJed Brown /* Solve J Y = F, where J is Jacobian matrix */ 33b79b07cfSJed Brown ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr); 34b79b07cfSJed Brown ierr = KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre,flg);CHKERRQ(ierr); 35b79b07cfSJed Brown ierr = KSPSolve(snes->ksp,F,Y);CHKERRQ(ierr); 36b79b07cfSJed Brown ierr = KSPGetConvergedReason(snes->ksp,&kspreason);CHKERRQ(ierr); 37b79b07cfSJed Brown if (kspreason < 0 && ++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) { 38b79b07cfSJed 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); 39b79b07cfSJed Brown snes->reason = SNES_DIVERGED_LINEAR_SOLVE; 40b79b07cfSJed Brown } else { 41b79b07cfSJed Brown snes->reason = SNES_CONVERGED_ITS; 42b79b07cfSJed Brown } 43b79b07cfSJed Brown ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr); 44b79b07cfSJed Brown snes->linear_its += lits; 45b79b07cfSJed Brown ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr); 46b79b07cfSJed Brown snes->iter++; 47b79b07cfSJed Brown 48b79b07cfSJed Brown /* Take the computed step. */ 49b79b07cfSJed Brown ierr = VecAXPY(X,-1.0,Y);CHKERRQ(ierr); 50b79b07cfSJed Brown PetscFunctionReturn(0); 51b79b07cfSJed Brown } 52b79b07cfSJed Brown 53b79b07cfSJed Brown #undef __FUNCT__ 54b79b07cfSJed Brown #define __FUNCT__ "SNESSetUp_KSPONLY" 55b79b07cfSJed Brown static PetscErrorCode SNESSetUp_KSPONLY(SNES snes) 56b79b07cfSJed Brown { 57b79b07cfSJed Brown PetscErrorCode ierr; 58b79b07cfSJed Brown 59b79b07cfSJed Brown PetscFunctionBegin; 60b79b07cfSJed Brown if (!snes->vec_sol_update) { 61b79b07cfSJed Brown ierr = VecDuplicate(snes->vec_sol,&snes->vec_sol_update);CHKERRQ(ierr); 62b79b07cfSJed Brown ierr = PetscLogObjectParent(snes,snes->vec_sol_update);CHKERRQ(ierr); 63b79b07cfSJed Brown } 64b79b07cfSJed Brown PetscFunctionReturn(0); 65b79b07cfSJed Brown } 66b79b07cfSJed Brown 67b79b07cfSJed Brown #undef __FUNCT__ 68b79b07cfSJed Brown #define __FUNCT__ "SNESDestroy_KSPONLY" 69b79b07cfSJed Brown static PetscErrorCode SNESDestroy_KSPONLY(SNES snes) 70b79b07cfSJed Brown { 71b79b07cfSJed Brown PetscErrorCode ierr; 72b79b07cfSJed Brown 73b79b07cfSJed Brown PetscFunctionBegin; 74b79b07cfSJed Brown if (snes->vec_sol_update) { 75b79b07cfSJed Brown ierr = VecDestroy(snes->vec_sol_update);CHKERRQ(ierr); 76b79b07cfSJed Brown snes->vec_sol_update = PETSC_NULL; 77b79b07cfSJed Brown } 78b79b07cfSJed Brown PetscFunctionReturn(0); 79b79b07cfSJed Brown } 80b79b07cfSJed Brown 81b79b07cfSJed Brown /* -------------------------------------------------------------------------- */ 82b79b07cfSJed Brown /*MC 83b79b07cfSJed Brown SNESKSPONLY - Nonlinear solver that only performs one Newton step and does not compute any norms. 84b79b07cfSJed Brown The main purpose of this solver is to solve linear problems using the SNES interface, without 85b79b07cfSJed Brown any additional overhead in the form of vector operations. 86b79b07cfSJed Brown 87b79b07cfSJed Brown Level: beginner 88b79b07cfSJed Brown 89b79b07cfSJed Brown .seealso: SNESCreate(), SNES, SNESSetType(), SNESLS, SNESTR 90b79b07cfSJed Brown M*/ 91b79b07cfSJed Brown EXTERN_C_BEGIN 92b79b07cfSJed Brown #undef __FUNCT__ 93b79b07cfSJed Brown #define __FUNCT__ "SNESCreate_KSPONLY" 94*7087cfbeSBarry Smith PetscErrorCode SNESCreate_KSPONLY(SNES snes) 95b79b07cfSJed Brown { 96b79b07cfSJed Brown 97b79b07cfSJed Brown PetscFunctionBegin; 98b79b07cfSJed Brown snes->ops->setup = SNESSetUp_KSPONLY; 99b79b07cfSJed Brown snes->ops->solve = SNESSolve_KSPONLY; 100b79b07cfSJed Brown snes->ops->destroy = SNESDestroy_KSPONLY; 101b79b07cfSJed Brown 102b79b07cfSJed Brown snes->data = 0; 103b79b07cfSJed Brown PetscFunctionReturn(0); 104b79b07cfSJed Brown } 105b79b07cfSJed Brown EXTERN_C_END 106