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Is it possible to provide an initial guess for eigenvector(s) to the SLEPc eigen-solver?

0 votes
asked Oct 31, 2014 by edhech FEniCS Novice (120 points)

Hi, I don't think the current interface allows it. However if SLEPcEigenSolver returned the
pointer to the SLEPc solver it wraps what you are after could be achieved by EPSSetInitialSpace(EPS eps,PetscInt n,Vec *is). Is that correct? If so, maybe register a feature request on bitbucket.

commented Nov 4, 2014 by MiroK FEniCS Expert (80,920 points)

Hello MiroK,

I have not yet used SLEPc directly (i.e. without the dolfin interface), but perusing through the SLEPc documentation I got the idea that SLEPc routines do allow users to provide an initial guess (e.g. from a previous approximate solution). In particular I was thinking of an application in which one gets an initial approximation to eigenvectors on a relatively coarse mesh; these eigenvectors could then be projected to and used as initial guess on a refined mesh. That could potentially save many expensive iterations on the refined mesh, so it would be a desirable feature to have, don't you think?

commented Nov 6, 2014 by edhech FEniCS Novice (120 points)

Hi, I registered an enhancement issue for this.

commented Nov 7, 2014 by MiroK FEniCS Expert (80,920 points)
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