[petsc-users] Slepc SVDCyclicSetExplicitMatrix does not prealloc memory?

[Jose E. Roman]

On 01/04/2011, Gong Ding wrote:

> Hope the problem can be solved soon.
> And do you have some comment on how to solve the smallest singular value?
> I guess i am not on the right way since matlab (with arpack) can calculate smallest singular value.
> But I never make arpack work. 
> Even for smallest eigen value problem, arpack report no eigen value are found.    
> 

As discussed in section 3.3 of our report http://www.grycap.upv.es/slepc/documentation/reports/str8.pdf this is a difficult case. Probably the best choice is to use harmonic extraction in trlanczos. But this is not implemented in SLEPc, and there is no guarantee it works for difficult problems.

Jose