% GRID GRID Plot Grid Toggle Function
% 
% Usage
% 
% Toggles the drawing of grid lines on the currently active plot.  The
% general syntax for its use is
% 
%    grid(state)
% 
% where state is either
% 
%    grid('on')
% 
% to activate the grid lines, or
% 
%    grid('off')
% 
% to deactivate the grid lines.  If you specify no argument then
% grid toggles the state of the grid:
% 
%    grid
% 
% You can also specify a particular axis to the grid command
% 
%    grid(handle,...)
% 
% where handle is the handle for a particular axis.

% Copyright (c) 2002-2006 Samit Basu

function h = grid(varargin)
if (nargin == 0)
     grid_toggle(gca);
elseif (strcomp(varargin{1},'on'))
     grid_on(gca);
elseif (strcomp(varargin{1},'off'))
     grid_off(gca);
elseif (ishandle(varargin{1}))
   if (nargin == 1)
     grid_toggle(varargin{1})
   elseif (strcomp(varargin{2},'on'))
     grid_on(varargin{1});
   elseif (strcomp(varargin{2},'off'))
     grid_off(varargin{1});
   else
     error('Unrecognized form of grid');
   end
else
   error('Unrecognized arguments to grid');
end


function grid_toggle(handle);
  if (strcomp(get(gca,'xgrid'),'on') | ...
      strcomp(get(gca,'ygrid'),'on') | ...
      strcomp(get(gca,'zgrid'),'on'))
     grid_off(handle);
  else
     grid_on(handle);
  end

function grid_off(handle)
  set(gca,'xgrid','off');
  set(gca,'ygrid','off');
  set(gca,'zgrid','off');

function grid_on(handle)
  set(gca,'xgrid','on');
  set(gca,'ygrid','on');
  set(gca,'zgrid','on');