petsc-3.9.4 2018-09-11

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" 
PetscErrorCode  KSPSetInitialGuessNonzero(KSP ksp,PetscBool flg)

Logically Collective on KSP

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 keys

-ksp_initial_guess_nonzero : use nonzero initial guess; this takes an optional truth value (0/1/no/yes/true/false) -

Notes

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

Keywords

set, initial guess, nonzero

Level

beginner

Location

src/ksp/ksp/interface/itfunc.c

Examples