slepc3.20.1 20231127
EPSSetDeflationSpace
Specify a basis of vectors that constitute the deflation space.
Synopsis
#include "slepceps.h"
PetscErrorCode EPSSetDeflationSpace(EPS eps,PetscInt n,Vec v[])
Collective
Input Parameters
 eps   the eigenproblem solver context

 n   number of vectors

 v   set of basis vectors of the deflation space

Notes
When a deflation space is given, the eigensolver seeks the eigensolution
in the restriction of the problem to the orthogonal complement of this
space. This can be used for instance in the case that an invariant
subspace is known beforehand (such as the nullspace of the matrix).
These vectors do not persist from one EPSSolve() call to the other, so the
deflation space should be set every time.
The vectors do not need to be mutually orthonormal, since they are explicitly
orthonormalized internally.
See Also
EPSSetInitialSpace()
Level
intermediate
Location
src/eps/interface/epssetup.c
Examples
src/eps/tutorials/ex7.c
src/eps/tutorials/ex11.c
Index of all EPS routines
Table of Contents for all manual pages
Index of all manual pages