C ======================================================================
  C === AMD_cross ========================================================
  C ======================================================================
  
  C ----------------------------------------------------------------------
  C AMD, Copyright (c) by Timothy A. Davis, Patrick R.
  C Amestoy, and Iain S. Duff.  See ../README.txt for
  C License.  email: davis at cise.ufl.edu    CISE Department, Univ. of
  C Florida.  web: http://www.cise.ufl.edu/research/sparse/amd
  C ----------------------------------------------------------------------
  
  C This program provides an example of how to call the C version of AMD
  C from a Fortran program.  It is HIGHLY non-portable.
  
  C The amd_order routine returns PERM (1) < 0 if an error occurs.
  C (-1: out of memory, -2: invalid matrix)
  
  C Note that the input matrix is 0-based.  From Fortran, column j of the
  C matrix is in AI (AP (I)+1 ... AP (I+1)).  The row indices in this
  C set are in the range 0 to N-1.  To demonstrate this translation,
  C the input matrix is printed in 1-based form.  This program uses
  C the same 5-by-5 test matrix as amd_simple.c.
  
          INTEGER N, NZ, K, P
          PARAMETER (N = 5, NZ = 14)
          INTEGER AP (N+1), AI (NZ), PERM (N)
          DATA AP / 0,   2,       6,       10,  12, 14 /
          DATA AI / 0,1, 0,1,2,4, 1,2,3,4, 2,3, 1,4    /
          DOUBLE PRECISION CONTROL (5), INFO (20)
  
  C       print the input matrix
          PRINT 10, N, N, NZ
  10      FORMAT ('Input matrix:', I2, '-by-', I2, ' with',I3,' entries')
          DO 40 J = 1, N
              PRINT 20, J, AP (J+1) - AP (J), AP (J)+1, AP (J+1)
  20          FORMAT ( /, 'Column: ', I2, ' number of entries: ', I2,
       $          ' with row indices in AI (', I3, ' ... ', I3, ')')
              PRINT 30, ((AI (P) + 1), P = AP (J) + 1, AP (J+1))
  30          FORMAT ('    row indices: ', 24I3)
  40      CONTINUE
  
          CALL AMDDEFAULTS (CONTROL)
          CALL AMDORDER (N, AP, AI, PERM, CONTROL, INFO)
          CALL AMDINFO (INFO)
  
          DO 60 K = 1, N
              PRINT 50, K, PERM (K) + 1
  50          FORMAT ('PERM (',I2,') = ', I2)
  60      CONTINUE
          END