## 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] =} __plt2__ (@var{x1}, @var{x2}, @var{fmt})
## @end deftypefn

## Author: jwe

function [data, fmtstr, key] = __plt2__ (x1, x2, fmt, keystr)

  if (nargin < 2 || nargin > 4 || nargout < 2 || nargout > 3)
    print_usage ();
  endif

  if (nargin < 3)
    fmt = {""};
  endif

  if (nargin < 4)
    keystr = {""};
  endif

  if (! iscellstr (fmt))
    error ("__plt1__: fmt must be a cell array of character strings");
  endif

  if (! iscell (keystr))
    error ("__plt1__: fmt must be a cell array");
  endif

  if (any (any (imag (x1))))
    x1 = real (x1);
  endif

  if (any (any (imag (x2))))
    x2 = real (x2);
  endif

  if (isscalar (x1))
    if (isscalar (x2))
      [data, fmtstr, key] = __plt2ss__ (x1, x2, fmt, keystr);
    else
      error ("__plt2__: invalid data for plotting");
    endif
  elseif (isvector (x1))
    if (isvector (x2))
      [data, fmtstr, key] = __plt2vv__ (x1, x2, fmt, keystr);
    elseif (ismatrix (x2))
      [data, fmtstr, key] = __plt2vm__ (x1, x2, fmt, keystr);
    else
      error ("__plt2__: invalid data for plotting");
    endif
  elseif (ismatrix (x1))
    if (isvector (x2))
      [data, fmtstr, key] = __plt2mv__ (x1, x2, fmt, keystr);
    elseif (ismatrix (x2))
      [data, fmtstr, key] = __plt2mm__ (x1, x2, fmt, keystr);
    else
      error ("__plt2__: invalid data for plotting");
    endif
  elseif (isempty (x1) && isempty (x2))
    data = {};
    fmtstr = {};
    key = {};
  else
    error ("__plt2__: invalid data for plotting");
  endif

endfunction