[petsc-users] Get a smaller vector with PETSc

[Analabha Roy]

On Sun, Oct 6, 2013 at 7:29 AM, Barry Smith <bsmith at mcs.anl.gov> wrote:

>
>   VecScatterCreate().
>


What about VecGetSubVector()<http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Vec/VecGetSubVector.html>?



>
>    If you wish the sub vector to live on a single process then create a
> sequential vector of the appropriate size on that one process and
> sequential vectors of size zero on all other processes and scatter into
> them.
>
>    Barry
>
> On Oct 2, 2013, at 6:27 AM, Rui Emanuel Ferreira da Silva <
> rui.silva at uam.es> wrote:
>
> > I am writing to you to ask some technical problems that I am dealing
> > with the use of PETSc.
> >
> > The problem that I am facing is the following: I have defined a vector
> in Petsc which was created with VecCreateMPI. After that, I read this
> vector from an external file with a PETSc viewer.
> >
> > So if the initial vector is V with size N, I want to obtain a smaller
> vector U with size M, where M<N. I have an array of integers that are the
> indexes of V that I want to pass to U.
> >
> > How can I do this?
> >
> > Regards
> >
> > -------------------
> > Rui Silva
> > EMTCCM (European Master in Theoretical Chemistry and Computational
> Modelling)
> > UAM, Departamento de Química, Módulo 13
> > CAMPUS
> http://www.uam.es/departamentos/ciencias/quimica/spline/index.html
> > -------------------
> >
>
>


-- 
---
*Analabha Roy*
C.S.I.R <http://www.csir.res.in>  Senior Research
Associate<http://csirhrdg.res.in/poolsra.htm>
Saha Institute of Nuclear Physics <http://www.saha.ac.in>
Section 1, Block AF
Bidhannagar, Calcutta 700064
India
*Emails*: daneel at physics.utexas.edu, hariseldon99 at gmail.com
*Webpage*: http://www.ph.utexas.edu/~daneel/
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