[petsc-users] Large Matrix eigenvalue problem : configuration

[Jose E. Roman]

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
>