Overhaul ez* family of plot functions. * scripts/plot/ezcontour.m, scripts/plot/ezcontourf.m, scripts/plot/ezmesh.m, scripts/plot/ezmeshc.m, scripts/plot/ezpolar.m, scripts/plot/ezsurfc.m: Redo docstring. Match function output names to docstring. * scripts/plot/ezplot.m: Add %!demo block with sinc function. Redo docstring. Match function output names to docstring. scripts/plot/ezplot3.m: Add %!demo block showing 'animate' option. Redo docstring. Match function output names to docstring. * scripts/plot/ezsurf.m: Add %!demo block showing 'circ' argument. Redo docstring. Match function output names to docstring. * scripts/plot/private/__ezplot__.m: Implement 'circ' option for ezsurf, ezmesh. Implement 'animate' option for ezplot3. Implement new algorithm for finding valid axis setting for mesh, surf, contour plots based on function gradient. Eliminate complex Z values along with singularities because these are not plottable by mesh, surf. Implement Matlab-compatible 2-pass approach to finding valid domain for plot. Use 500 points for point-style plot functions ezplot, ezplot3, ezpolar rather than previous 60 for a smoother plot. Use better regexprep() calls to format "pretty print" title string. Relax input checking and allow 3rd parametric function to be a function of 1 variable only. Clean up code and use Octave coding conventions.

## Copyright (C) 2005-2012 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 3 of the License, 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, see
## <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn {Function File} {} closereq ()
## Close the current figure and delete all graphics objects associated
## with it.
## @seealso{close, delete}
## @end deftypefn

## Author: jwe

function closereq ()

  if (nargin == 0)
    cf = gcbf ();
    if (isempty (cf))
      warning ("closereq: calling closereq from octave prompt is not supported, use 'close' instead");
      cf = get (0, "currentfigure");
    endif
    if (! isempty (cf) && isfigure (cf))
      delete (cf);
    endif
  else
    print_usage ();
  endif

endfunction