SUBROUTINE sla_MXM (A, B, C) *+ * - - - - * M X M * - - - - * * Product of two 3x3 matrices: * matrix C = matrix A x matrix B * * (single precision) * * Given: * A real(3,3) matrix * B real(3,3) matrix * * Returned: * C real(3,3) matrix result * * To comply with the ANSI Fortran 77 standard, A, B and C must * be different arrays. However, the routine is coded so as to * work properly on many platforms even if this rule is violated. * * Last revision: 26 December 2004 * * Copyright P.T.Wallace. All rights reserved. * * License: * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program (see SLA_CONDITIONS); if not, write to the * Free Software Foundation, Inc., 59 Temple Place, Suite 330, * Boston, MA 02111-1307 USA * *- IMPLICIT NONE REAL A(3,3),B(3,3),C(3,3) INTEGER I,J,K REAL W,WM(3,3) * Multiply into scratch matrix DO I=1,3 DO J=1,3 W=0.0 DO K=1,3 W=W+A(I,K)*B(K,J) END DO WM(I,J)=W END DO END DO * Return the result DO J=1,3 DO I=1,3 C(I,J)=WM(I,J) END DO END DO END