clear all;
close all;
clc;
N=25;
L=1;
x2=linspace(-L,L,N+1);
x=x2(1:N);
dx=x(2)-x(1);
k=.01;
e=ones(N,1);
A=spdiags([e -2*e e],-1:1,N,N);
A(1,N)=1; A(N,1)=1;
tspan=[0 10];

y2=linspace(-L,L,N+1);
y=y2(1:N);
dy=y(2)-y(1);
I=eye(N,N);
B=kron(I,A)+kron(A,I);

[X,Y]=meshgrid(x,y);
U0=exp(-X.^2-Y.^2);
uu0=reshape(U0,N^2,1);
[t,uu]=ode45('pderhsnew',tspan,uu0,[],k,dx,B,N);
for i=1:length(t)
    surf(X,Y,reshape(uu(i,:),N,N))
    axis([-1 1 -1 1 0 1])
    F(i)=getframe;
end
movie(F)