EPSGetStartVector

Gets a vector to be used as the starting vector in an Arnoldi or Lanczos reduction.

Synopsis

#include "slepceps.h" 
PetscErrorCode EPSGetStartVector(EPS eps,int i,Vec vec,PetscTruth *breakdown)
Collective on EPS and Vec

Input Parameters

eps - the eigensolver context
i - index of the Arnoldi/Lanczos step

Output Parameters

vec - the start vector
breakdown - flag indicating that a breakdown has occurred

Notes

The start vector is computed from another vector: for the first step (i=0), the initial vector is used (see EPSGetInitialVector()); otherwise a random vector is created. Then this vector is forced to be in the range of OP and orthonormalized with respect to all V-vectors up to i-1.

The flag breakdown is set to true if either i=0 and the vector belongs to the deflation space, or i>0 and the vector is linearly dependent with respect to the V-vectors.

The caller must pass a vector already allocated with dimensions conforming to the initial vector. This vector is overwritten.

See Also

EPSGetInitialVector()

Location: src/eps/interface/solve.c
Index of all EPS routines
Table of Contents for all manual pages
Index of all manual pages