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SUBROUTINE sla_IMXV (RM, VA, VB)
*+
* - - - - -
* I M X V
* - - - - -
*
* Performs the 3-D backward unitary transformation:
*
* vector VB = (inverse of matrix RM) * vector VA
*
* (single precision)
*
* (n.b. the matrix must be unitary, as this routine assumes that
* the inverse and transpose are identical)
*
* Given:
* RM real(3,3) matrix
* VA real(3) vector
*
* Returned:
* VB real(3) result vector
*
* P.T.Wallace Starlink November 1984
*
* 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., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307 USA
*
*-
IMPLICIT NONE
REAL RM(3,3),VA(3),VB(3)
INTEGER I,J
REAL W,VW(3)
* Inverse of matrix RM * vector VA -> vector VW
DO J=1,3
W=0.0
DO I=1,3
W=W+RM(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