x=linspace(-10,10,100);
M = repmat(struct('cdata',{[]},'colormap',{[]}),1,21); %Preallocates space
%for movie structure M
for j=1:21
    t=(j-1)/5;
    u=exp(-(x-2*t).^2);
    plot(x,u);
    axis([-10,10,0,2])
    xlabel('x')
    ylabel('u')
    M(j)=getframe(gcf);
end
axes('Position',[0 0 1 1])
movie(M,5) %This plays the movie 5 times. To see it play just once, use movie(M)