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