[Pw_forum] ZGEMM or MATMUL for MPI environment

[Paolo Giannozzi]

On Wed, Aug 31, 2016 at 10:33 PM, Ilya Ryabinkin <igryabinkin at gmail.com>
wrote:

> So, the bottom line: ZGEMM and MATMUL should give the same, right?
>

If properly used, yes, they should give the same results.

> S is not distributed: CALL calbec( npw, evcold, evc, S ) computes
> >   S(ibnd,jbnd) = \sum_{i=1}^npw evcold^*(i,ibnd) evc(i,jbnd)
>

... summed over all processors, of course

Paolo


> >
> > Paolo
> >
> > On Wed, Aug 31, 2016 at 9:54 PM, Ilya Ryabinkin <igryabinkin at gmail.com>
> > wrote:
> >>
> >> > If the matrix S is not distributed (and if you have a copy of it on
> each
> >> > processor), MATMUL (evc, S) will be distributed exactly in the same
> way
> >> > as
> >> > evc
> >>
> >> How do I know if it is distributed? I got it through
> >>
> >>  CALL calbec( npw, evcold, evc, S )
> >>
> >> --
> >> I.
> >>
> >> >
> >> > Paol
> >> >
> >> > On Wed, Aug 31, 2016 at 9:16 PM, Ilya Ryabinkin <
> igryabinkin at gmail.com>
> >> > wrote:
> >> >>
> >> >> Colleagues:
> >> >> I'm wondering what should I use to get the matrix product evc*S,
> where
> >> >>    evc  = evc(npw, nbnd)
> >> >> is a collection of MOs and
> >> >>    S = S(nbnd, nbnd)
> >> >> if my code is executed on several MPI nodes?
> >> >>
> >> >> I see that for for nproc >1
> >> >>
> >> >> npw is actually npw/nproc, which brings a question what is happening
> >> >> in the MATMUL(evc, S)
> >> >>
> >> >>
> >> >> Ilya
> >> >>
> >> >> --
> >> >> *******************************************************
> >> >>                     Ilya Ryabinkin
> >> >>                  Postdoctoral Scholar
> >> >>           Physical and Environmental Sciences
> >> >>            University of Toronto Scarborough
> >> >>   http://www.utsc.utoronto.ca/~aizmaylov/Members.html
> >> >> *******************************************************
> >> >> _______________________________________________
> >> >> Pw_forum mailing list
> >> >> Pw_forum at pwscf.org
> >> >> http://pwscf.org/mailman/listinfo/pw_forum
> >> >
> >> >
> >> >
> >> >
> >> > --
> >> > Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
> >> > Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
> >> > Phone +39-0432-558216, fax +39-0432-558222
> >> >
> >> >
> >> > _______________________________________________
> >> > Pw_forum mailing list
> >> > Pw_forum at pwscf.org
> >> > http://pwscf.org/mailman/listinfo/pw_forum
> >>
> >>
> >>
> >> --
> >> *******************************************************
> >>                     Ilya Ryabinkin
> >>                  Postdoctoral Scholar
> >>           Physical and Environmental Sciences
> >>            University of Toronto Scarborough
> >>   http://www.utsc.utoronto.ca/~aizmaylov/Members.html
> >> *******************************************************
> >> _______________________________________________
> >> Pw_forum mailing list
> >> Pw_forum at pwscf.org
> >> http://pwscf.org/mailman/listinfo/pw_forum
> >
> >
> >
> >
> > --
> > Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
> > Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
> > Phone +39-0432-558216, fax +39-0432-558222
> >
> >
> > _______________________________________________
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://pwscf.org/mailman/listinfo/pw_forum
>
>
>
> --
> *******************************************************
>                     Ilya Ryabinkin
>                  Postdoctoral Scholar
>           Physical and Environmental Sciences
>            University of Toronto Scarborough
>   http://www.utsc.utoronto.ca/~aizmaylov/Members.html
> *******************************************************
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>



-- 
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20160831/197b89c2/attachment.html>