### Copyright (C) 1996 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, 59 Temple Place - Suite 330, Boston, MA
### 02111-1307, USA.

## usage: axis ()
##        axis ([xmin, xmax])
##        axis ([xmin, xmax, ymin, ymax])
##        axis ([xmin, xmax, ymin, ymax, zmin, zmax])
##
## Sets the axis limits.
##
## With no arguments, turns autoscaling on.
##
## If your plot is already drawn, then you need to REPLOT before 
## the new axis limits will take effect.

function curr_axis = axis (ax)

  ## This may not be correct if someone has used the gnuplot interface
  ## directly...

  global __current_axis__;

  if (! exist ("__current_axis__"))
    __current_axis__ = [-10, 10, -10, 10];
  endif

  if (nargin > 1)
    usage ("axis ([xmin, xmax, ymin, ymax, zmin, zmax])");
  endif

  if (nargin == 0)
    set autoscale;
    curr_axis = __current_axis__;
  elseif (is_vector (ax))

    len = length (ax);

    if (len != 2 && len != 4 && len != 6)
      error ("axis: expecting vector with 2, 4, or 6 elements");
    endif

    __current_axis__ = reshape (ax, 1, len);

    if (len > 1)
      eval (sprintf ("set xrange [%g:%g];", ax (1), ax (2)));
    endif

    if (len > 3)
      eval (sprintf ("set yrange [%g:%g];", ax (3), ax (4)));
    endif

    if (len > 5)
      eval (sprintf ("set zrange [%g:%g];", ax (5), ax (6)));
    endif

  else
    error ("axis: expecting no args, or a vector with 2, 4, or 6 elements");
  endif

endfunction