petsc-3.12.5 2020-03-29

KSPBuildResidual

Builds the residual in a vector provided.

#include "petscksp.h" 
PetscErrorCode  KSPBuildResidual(KSP ksp,Vec t,Vec v,Vec *V)

Collective on ksp

ksp -iterative context obtained from KSPCreate()

	v	- optional location to stash residual. If v is not provided, then a location is generated.
	t	- work vector. If not provided then one is generated.
	V	- the residual

Regardless of whether or not v is provided, the residual is returned in V.

advanced