STCheckNullSpace#

Tests if constraint vectors are nullspace vectors.

Synopsis#

#include "slepcst.h" 
PetscErrorCode STCheckNullSpace(ST st,BV V)

Collective

Input Parameters#

  • st - the spectral transformation context

  • V - basis vectors to be checked

Notes#

Given a basis vectors object, this function tests each of its constraint vectors to be a nullspace vector of the coefficient matrix of the associated KSP object. All these nullspace vectors are passed to the KSP object with MatSetNullSpace().

This function allows handling singular pencils (i.e., when \(A\) and \(B\) share a common nullspace), and solving some problems in which the nullspace is important.

See Also#

ST: Spectral Transformation, EPSSetDeflationSpace(), MatSetNullSpace()

Level#

developer

Location#

src/sys/classes/st/interface/stsles.c


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