PCNullSpaceAttach

attaches a null space to a preconditioner object. This null space will be removed from the resulting vector whenever the preconditioner is applied.

#include "petscsles.h" 
int PCNullSpaceAttach(PC pc,MatNullSpace nullsp)

Collective on PC

	pc	- the preconditioner context
	nullsp	- the null space object

Overwrites any previous null space that may have been attached

Section 4.15 Solving Singular Systems -

PC, destroy, null space