slepc-3.20.2 2024-03-15
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EPSSetInitialSpace

Specify a basis of vectors that constitute the initial space, that is, the subspace from which the solver starts to iterate.

Synopsis

#include "slepceps.h" 
PetscErrorCode EPSSetInitialSpace(EPS eps,PetscInt n,Vec is[])
Collective

Input Parameters

eps  - the eigenproblem solver context
n  - number of vectors
is  - set of basis vectors of the initial space

Notes

Some solvers start to iterate on a single vector (initial vector). In that case, the other vectors are ignored.

These vectors do not persist from one EPSSolve() call to the other, so the initial space should be set every time.

The vectors do not need to be mutually orthonormal, since they are explicitly orthonormalized internally.

Common usage of this function is when the user can provide a rough approximation of the wanted eigenspace. Then, convergence may be faster.

See Also

EPSSetLeftInitialSpace(), EPSSetDeflationSpace()

Level

intermediate

Location

src/eps/interface/epssetup.c

Examples

src/eps/tutorials/ex5.c
src/eps/tutorials/ex7.c
src/eps/tutorials/ex19.c
src/eps/tutorials/ex34.c
src/eps/tutorials/ex41.c


Index of all EPS routines
Table of Contents for all manual pages
Index of all manual pages