[petsc-users] ISCreateStride and MatGetSubmatrices

[Jed Brown]

On Tue, Aug 28, 2012 at 11:18 AM, shu guo <greatgs2008 at gmail.com> wrote:

> So I have to define this submatrix and extract is into this pre-set
> location?
>

No, you have to create an array to hold the Mat objects, e.g.

Mat submats(10)


>
> On Tue, Aug 28, 2012 at 12:03 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:
> > On Tue, Aug 28, 2012 at 10:56 AM, shu guo <greatgs2008 at gmail.com> wrote:
> >>
> >> Hi All,
> >>
> >> I think I made a mistake. It seems it crashes when I call the command
> >> of MatGetSubMatrices. There is an indication that saying,
> >>
> >>  MatGetSubmatrices() is slightly different from C since the
> >>      Fortran provides the array to hold the submatrix objects,while in C
> >> that
> >>      array is allocated by the MatGetSubmatrices()
> >>
> >> What does this mean? I don't even need this command to extract the
> >> submatrix?
> >
> >
> > It means that you have to allocate the array to hold the result.
> >
> > If this seems cumbersome to you, ask yourself why you chose to write in
> > Fortran. ;-)
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120828/44eda77a/attachment.html>