c Copyright (C) 2008 VZLU Prague, a.s., Czech Republic c c Author: Jaroslav Hajek <highegg@gmail.com> c c This file is part of OctGPR. c c OctGPR 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 2 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 dscrot(trans,n,D,Z,x) c purpose: perform a "rotate and scale" transformation, i.e. c given a diagonal matrix D and orthogonal matrix c W, this subroutine computes c x = W*D*x if (trans == 'N' or 'n') c x = W'*D*x if (trans == 'T' or 't') c arguments: c trans (in) indicates transposition c n (in) dimension c D (in) scale matrix c Z (in) orthogonal matrix c x (io) the vector being transformed c wrk workspace >= n c character trans integer n double precision D(n),Z(n,n),x(n) double precision wrk(n) integer i logical lsame external lsame if (lsame(trans,'T')) then call dgemv(trans,n,n,1d0,Z,n,x,1,0d0,wrk,1) do i = 1,n x(i) = wrk(i)*D(i) end do else do i = 1,n wrk(i) = x(i)*D(i) end do call dgemv(trans,n,n,1d0,Z,n,wrk,1,0d0,x,1) end if end subroutine

Generated by Doxygen 1.6.0 Back to index