[petsc-users] SLEPc eigensolver that uses minimal memory and finds ALL eigenvalues of a real symmetric sparse matrix in reasonable time

[Jed Brown]

On Mon, Aug 8, 2011 at 00:29, Shitij Bhargava <shitij.cse at gmail.com> wrote:

> I* *ran it with:
>
> mpirun -np 2 ./slepcEigenMPI -eps_monitor
>
> I didnt do exactly what you said, because the matrix generation part in the
> actual program is quite time consuming itself. But I assume what I am doing
> is equivalent to what you meant to do? Also, I put MPD as PETSC_DECIDE,
> because I didnt know what to put it for this matrix dimension.
>
> This is the output I get: (part of the output)
> *MATRIX ASSMEBLY DONE !!!!!!!!
>
> MATRIX ASSMEBLY DONE !!!!!!!!
>
>   1 EPS nconv=98 first unconverged value (error) 1490.88 (1.73958730e-05)
>   1 EPS nconv=98 first unconverged value (error) 1490.88 (1.73958730e-05)
>   2 EPS nconv=282 first unconverged value (error) 3.04636e-27
> (2.49532175e-04)
>   2 EPS nconv=282 first unconverged value (error) 3.04636e-27
> (2.49532175e-04)*


The most likely case is that you have more than one MPI implementation
installed and that you are running with a different implementation than you
built with. Compare the outputs:

$ ldd ./slepcEigenMPI
$ which mpirun
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