KSPSetInitialGuessNonzero

Tells the iterative solver that the initial guess is nonzero; otherwise KSP assumes the initial guess is to be zero (and thus zeros it out before solving).

Synopsis

#include "petscksp.h" 
#include "petscmat.h" 
PetscErrorCode KSPSetInitialGuessNonzero(KSP ksp, PetscBool flg)

Logically Collective

Input Parameters

• ksp - iterative context obtained from KSPCreate()

• flg - PETSC_TRUE indicates the guess is non-zero, PETSC_FALSE indicates the guess is zero

Options Database Key

• -ksp_initial_guess_nonzero <true,false> - use nonzero initial guess

Note

If this is not called the X vector is zeroed in the call to KSPSolve().

See Also

KSP: Linear System Solvers, KSPGetInitialGuessNonzero(), KSPGuessSetType(), KSPGuessType, KSP

Level

beginner

Location

src/ksp/ksp/interface/itfunc.c

Examples

src/ksp/ksp/tutorials/ex71.c
src/ksp/ksp/tutorials/ex6f.F90
src/ksp/ksp/tutorials/ex9.c
src/ksp/ksp/tutorials/ex27.c
src/ksp/ksp/tutorials/ex51.c
src/ksp/ksp/tutorials/ex72.c
src/ksp/pc/tutorials/ex2.c
src/ksp/pc/tutorials/ex1.c
src/ksp/ksp/tutorials/ex84.c
src/ksp/ksp/tutorials/ex56.c

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Index of all KSP routines
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Index of all manual pages