## Copyright (C) 1996, 1997 John W. Eaton
##
## This file is part of Octave.
##
## Octave 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, or (at your option)
## any later version.
##
## Octave 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 Octave; see the file COPYING.  If not, write to the Free
## Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
## 02110-1301, USA.

## -*- texinfo -*-
## @deftypefn {Function File} {[data, fmtstr] =} __plt2mm__ (@var{x}, @var{y}, @var{fmt})
## @end deftypefn

## Author: jwe

function [data, fmtstr] = __plt2mm__ (x, y, fmt)

  if (nargin < 2 || nargin > 3 || nargout != 2)
    usage ("[data, fmtstr] = __plt2mm__ (x, y, fmt)");
  elseif (nargin == 2 || isempty (fmt))
    fmt = " ";  ## Yes, this is intentionally not an empty string!
  endif

  [x_nr, x_nc] = size (x);
  [y_nr, y_nc] = size (y);

  k = 1;
  fmt_nr = rows (fmt);
  if (x_nr == y_nr && x_nc == y_nc)
    if (x_nc > 0)
      if (rows (fmt) == 1)
	fmt = repmat (fmt, x_nc, 1);
      endif
      tmp = [x, y];
      dtmp = cell (x_nc, 1);
      ftmp = cell (x_nc, 1);
      for i = 1:x_nc
	dtmp{i} = tmp(:,[i,x_nc+i]);
	ftmp{i} = deblank (fmt(i,:));
      endfor
      data = dtmp;
      fmtstr = ftmp;
    else
      error ("__plt2mm__: arguments must be a matrices");
    endif
  else
    error ("__plt2mm__: matrix dimensions must match");
  endif

endfunction