Re: ATLAS binding: error when multiplying a complex matrix by a real matrix
"Oswin Krause" <[email protected]>
| Newsgroups | gmane.comp.lib.boost.ublas |
|---|---|
| Message-ID | <[email protected]> |
As an additional note: if your matrices are so big that you can't afford the copy of the whole matrix, you can as well just copy only a few rows at a time(assuming the left argument being complex) and do a blockwise multiplication, i.e. one call to gemm for every block and re/im-part. Most implementations of gemm do this step internally anyway, so a whole copy is likely only a waste of memory. On 2012-09-28 18:18, Michael Lehn wrote: > Am 28.09.2012 um 18:05 schrieb Florent Teichteil: > >> Thank you very much for your response. >> >> Actually, ublas does support it, at least multiplication of complex >> matrix by a real one (the other way gives a compilation error): > > Ok, but compared to using an optimized BLAS implementation will beat > the generic implementation of ublas by far. For big matrices the > performance gain by using ATLAS will most certainly compensate the > extra copying (assuming you have enough memory and allocate the extra > matrix only once). I think this is at least worth trying. > > Cheers, > > Michael > > >> >> ublas::axpy_prod(C, R, O) -> works >> ublas::axpy_prod(R, C, O) -> does not work >> >> where C is complex, R is real, and O is complex >> >> Cheers >> Florent >> >> Le 28/09/2012 17:42, Michael Lehn a écrit : >>> Am 28.09.2012 um 17:22 schrieb Florent Teichteil: >>> >>>> Hi all, >>>> >>>> I am trying to multiply a complex matrix by a real one using gemm: >>>> >>>> atlas::gemm(m1, m2, r); >>>> >>> >>> This operation is not supported by ATLAS (or any other standard >>> BLAS implementation). >>> >>> cheers, >>> >>> Michael >>> >>> _______________________________________________ >>> ublas mailing list >>> [email protected] >>> http://lists.boost.org/mailman/listinfo.cgi/ublas >>> Sent to: [email protected] >>> >> _______________________________________________ >> ublas mailing list >> [email protected] >> http://lists.boost.org/mailman/listinfo.cgi/ublas >> Sent to: [email protected] >> >> > > _______________________________________________ > ublas mailing list > [email protected] > http://lists.boost.org/mailman/listinfo.cgi/ublas > Sent to: [email protected] _______________________________________________ ublas mailing list [email protected] http://lists.boost.org/mailman/listinfo.cgi/ublas Sent to: [email protected]