[petsc-users] Large Matrix eigenvalue problem : configuration

[Alp Kalpalp]

Hi,

While reading the link you gave, I have seen a strange sentence;

"Otherwise you will get strange crashes."

can someone explain it why?

On Sun, May 17, 2015 at 12:16 PM, Jose E. Roman <jroman at dsic.upv.es> wrote:

> http://www.mcs.anl.gov/petsc/documentation/faq.html#with-64-bit-indices
>
>
>
> El 17/05/2015, a las 09:02, venkatesh g escribió:
>
> > Thank you. So the single eigenvector's size which is Nx1 is the number
> of unknowns and should be less than 2^31-1 so as to avoid configuring with
> '--with-64-bit-indices=1' ??
> >
> >
> > On Sat, May 16, 2015 at 8:05 PM, Matthew Knepley <knepley at gmail.com>
> wrote:
> > On Sat, May 16, 2015 at 3:49 AM, venkatesh g <venkateshgk.j at gmail.com>
> wrote:
> > Hi,
> >
> > I am trying to solving AX=lambda BX
> >
> > A and B are of size 57000 x 57000
> >
> > Currently I solve my small matrices using -st_type sinvert and -eps_nev 1
> >
> > So I get 1 eigenvalue and eigenvector.
> >
> > So for the 57000x57000 large matrix problem, the unknown eigenvector is
> 57000x1
> >
> > Should I configure the petsc as '--with-64-bit-indices=1' for this
> problem ?
> >
> > It is not necessary.
> >
> >    Matt
> >
> > Is the unknowns being considered as the entire eigenspace 57000x57000 ?
> >
> > kindly let me know.
> >
> > Venkatesh
> >
> >
> >
> >
> > --
> > What most experimenters take for granted before they begin their
> experiments is infinitely more interesting than any results to which their
> experiments lead.
> > -- Norbert Wiener
> >
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20150519/06e01a88/attachment.html>