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 linear eigensolver 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#

EPS: Eigenvalue Problem Solver, EPSSetInitialSpace()

Level#

intermediate

Location#

src/eps/interface/epssetup.c

Examples#

src/eps/tutorials/ex11.c
src/eps/tutorials/ex7.c

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