C     $Revision: 1.7 $
C=======================================================================

C     
C     dblmat.f
C     example for illustrating how to use %val
C     doubles the input matrix. The demo only handles real part of input.
C     NOTE: if your FORTRAN compiler does not support %val, 
C     use mxCopy_routine.
C
C     This is a MEX-file for MATLAB.
C     Copyright (c) 1984-98 by The MathWorks, Inc.
C=======================================================================


















C     computational subroutine
      subroutine dbl_mat(out_mat, in_mat, size)
      integer size, i
      real*8  out_mat(*), in_mat(*)

      do 10 i=1,size
         out_mat(i) = 2*in_mat(i)
 10   continue

      return
      end

C     gateway subroutine

      subroutine mexfunction(nlhs, plhs, nrhs, prhs)
C-----------------------------------------------------------------------
C     (integer) Replace integer by integer*8 on the DEC Alpha and the
C     SGI 64-bit platforms
C
      integer plhs(*), prhs(*)
      integer pr_in, pr_out
      integer mxGetPr, mxCreateFull
C-----------------------------------------------------------------------
C
      integer nlhs, nrhs, mxGetM, mxGetN
      integer m_in, n_in, size

      if(nrhs .ne. 1) then
         call mexErrMsgTxt('One input required.')
      endif
      if(nlhs .gt. 1) then
         call mexErrMsgTxt('Less than one output required.')
      endif
         
      m_in = mxGetM(prhs(1))
      n_in = mxGetN(prhs(1))
      size = m_in * n_in
      pr_in = mxGetPr(prhs(1))
      plhs(1) = mxCreateFull(m_in, n_in, 0)
      pr_out = mxGetPr(plhs(1))

C     call the computational routine
      call dbl_mat(%val(pr_out), %val(pr_in), size)

      return
      end