odewbar(t,y,flag,varargin)

function status = odewbar(t,y,flag,varargin)
%ODEWBAR Graphical waitbar printing ODE solver progress.
%   When the function odewbar is passed to an ODE solver as the 'OutputFcn'
%   property, i.e. options = odeset('OutputFcn',@odewbar), the solver calls 
%   ODEWBAR(T,Y,'') after every timestep. The ODEWBAR function shows a
%   waitbar with the progress of the integration every 0.2 seconds.
%   
%   At the start of integration, a solver calls ODEWBAR(TSPAN,Y0,'init') to
%   initialize the output function.  After each integration step to new time
%   point T with solution vector Y the solver calls STATUS = ODEWBAR(T,Y,'').
%	When the integration is complete, the solver calls ODEWBAR([],[],'done').
%
%   See also ODEPLOT, ODEPHAS2, ODEPHAS3, ODE45, ODE15S, ODESET.

%   Jos Pina, 22-11-2006
%	

persistent tfinal hwbar tlast

% regular call -> increment wbar
if nargin < 3 || isempty(flag)
	
	% update only if more than 0.2 sec elapsed
 	if cputime-tlast>0.2
 		tlast = cputime;
		waitbar(t/tfinal,hwbar);
 	% terminate if less than one second elapsed
 	else
 		status = 0;
 		return
 	end

% initialization / end
else
  switch(flag)
  case 'init'               % odeprint(tspan,y0,'init')
	  hwbar = waitbar(0,'ODE integration','Name','ODE integration');
	  tfinal = t(end);
	  tlast = cputime;
    
  case 'done'               % odeprint([],[],'done')
	close(hwbar)    
	  
  end
end

status = 0;