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 the VAX and many other systems even if this * rule is violated. * * P.T.Wallace Starlink 5 April 1990 * * Copyright (C) 1995 Rutherford Appleton Laboratory *- 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