[petsc-users] all eigen values

[Jose E. Roman]

El 02/12/2014, a las 09:20, siddhesh godbole escribió:

> Hello ,
> 
> I am a novice in using PETSC. Right now I am solving a cantilever beam vibration problem with PETSc in which i am using SLEPc to compute the eigen values. But in order to diagonalize the K and M matrices i need a full eigen matrix and all eigen values.
> What i see from all the tutorial help related to SLEPc is that it computes only certain number of eigenvalues which fall in some range or order. 
> 
> Please clarify me if i am ignorant about full usage of SLEPc and kindly suggest some way out.
> 
> sincerely
> 
> Siddhesh M Godbole
> IIT Madras

SLEPc is intended for large-scale eigenproblems, where you compute only part of the eigenvalue/eigenvector pairs because computing/storing all of them would be unaffordable. For small-medium problems use LAPACK or ScaLAPACK.

Jose