SUBROUTINE slDIMV (DM, VA, VB) *+ * - - - - - - * D I M V * - - - - - - * * Performs the 3-D backward unitary transformation: * * vector VB = (inverse of matrix DM) * vector VA * * (double precision) * * (n.b. the matrix must be unitary, as this routine assumes that * the inverse and transpose are identical) * * Given: * DM dp(3,3) matrix * VA dp(3) vector * * Returned: * VB dp(3) result vector * * P.T.Wallace Starlink March 1986 * * Copyright (C) 1995 Rutherford Appleton Laboratory * * 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., 51 Franklin Street, Fifth Floor, * Boston, MA 02110-1301 USA * * Copyright (C) 1995 Association of Universities for Research in Astronomy Inc. *- IMPLICIT NONE DOUBLE PRECISION DM(3,3),VA(3),VB(3) INTEGER I,J DOUBLE PRECISION W,VW(3) * Inverse of matrix DM * vector VA -> vector VW DO J=1,3 W=0D0 DO I=1,3 W=W+DM(I,J)*VA(I) END DO VW(J)=W END DO * Vector VW -> vector VB DO J=1,3 VB(J)=VW(J) END DO END