www.pudn.com > NumericalComputingwithMatlabCode.zip > brownian.m, change:2003-10-31,size:415b


% BROWNIAN   Two-dimensional random walk. 
%   What is the expansion rate of the cloud of particles? 
 
shg 
clf 
set(gcf,'doublebuffer','on') 
delta = .002; 
x = zeros(100,2); 
h = plot(x(:,1),x(:,2),'.'); 
axis([-1 1 -1 1]) 
axis square 
stop = uicontrol('style','toggle','string','stop'); 
while get(stop,'value') == 0 
   x = x + delta*randn(size(x)); 
   set(h,'xdata',x(:,1),'ydata',x(:,2)) 
   drawnow 
end