program test
*
* File:    ~/numerical/test_la.f
*
* Author:  Chuck Gartland (6-99, 10-01, 10-05)
*
* Fortran test program for using LAPACK on the Linux machines on the
* Kent Math/CS Network.
*
* Library locations:
*
*     LAPACK:  /usr/lib/liblapack.[a|so|...]
*     BLAS:    /usr/lib/libblas.[a|so|...]
*
* Compiling:
*
*     $ f77 test_la.f -llapack
*
*   See man page for "g77".
*
* Test prob: [ 1 2 3 ][x]   [ 6] ,  w/ true sol'n  [1]
*            [ 4 5 6 ][y] = [15]                   [1]
*            [ 7 8 0 ][z]   [15]                   [1]
*
      character*1 trans

      dimension A(4,5), b(3), ipiv(3)   ! deliberately chosen larger dimensions
                                        ! to illustrate role of 'lda'

      data A / 1., 4., 7., 0., 2., 5., 8., 0., 3., 6., 0., 0., 8*0. /
      data b / 6., 15., 15. /
      data trans, m, n, lda, ldb, nrhs / 'N', 3, 3, 4, 3, 1 /

      call sgetrf( m, n, A, lda, ipiv, info )                      ! LU-factor

      print *, ' info, ipiv = ', info, ipiv

      call sgetrs( trans, n, nrhs, A, lda, ipiv, b, ldb, info )    ! back solve

      print *, ' info, b = ', info, b

      stop
      end
*
* Appended sample output:
*
*  info, ipiv =  0 3 3 3
*  info, b =  0  1.00000012  0.999999881  1.
*