Mercurial > octave-nkf
view libcruft/blas-xtra/ddot3.f @ 14026:3781981be535 ss-3-5-90
snapshot 3.5.90
* configure.ac (AC_INIT): Version is now 3.5.90.
(OCTAVE_API_VERSION_NUMBER): Now 46.
(OCTAVE_RELEASE_DATE): Now 2011-12-11.
author | John W. Eaton <jwe@octave.org> |
---|---|
date | Sun, 11 Dec 2011 23:18:31 -0500 |
parents | e81ddf9cacd5 |
children | 72c96de7a403 |
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c Copyright (C) 2009-2011 VZLU Prague, a.s., Czech Republic c c Author: Jaroslav Hajek <highegg@gmail.com> c c This file is part of Octave. c c Octave is free software; you can redistribute it and/or modify c it under the terms of the GNU General Public License as published by c the Free Software Foundation; either version 3 of the License, or c (at your option) any later version. c c This program is distributed in the hope that it will be useful, c but WITHOUT ANY WARRANTY; without even the implied warranty of c MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the c GNU General Public License for more details. c c You should have received a copy of the GNU General Public License c along with this software; see the file COPYING. If not, see c <http://www.gnu.org/licenses/>. c subroutine ddot3(m,n,k,a,b,c) c purpose: a 3-dimensional dot product. c c = sum (a .* b, 2), where a and b are 3d arrays. c arguments: c m,n,k (in) the dimensions of a and b c a,b (in) double prec. input arrays of size (m,k,n) c c (out) double prec. output array, size (m,n) integer m,n,k,i,j,l double precision a(m,k,n),b(m,k,n) double precision c(m,n) double precision ddot external ddot c quick return if possible. if (m <= 0 .or. n <= 0) return if (m == 1) then c the column-major case. do j = 1,n c(1,j) = ddot(k,a(1,1,j),1,b(1,1,j),1) end do else c We prefer performance here, because that's what we generally c do by default in reduction functions. Besides, the accuracy c of xDOT is questionable. Hence, do a cache-aligned nested loop. do j = 1,n do i = 1,m c(i,j) = 0d0 end do do l = 1,k do i = 1,m c(i,j) = c(i,j) + a(i,l,j)*b(i,l,j) end do end do end do end if end subroutine