function classical=u(h,r)
k=r*(h^2);
x=0:h:1;
t=0:k:0.005;
m=size(x');
n=size(t');
u=1:1:m;
for i=1:m
    u(i)=sin(pi*(i-1)*h);
end
for i=1:n-1
    for j=2:m-1
        u(1)=0;
        u(m)=0;
        u(j)=r*u(j-1)+(1-2*r)*u(j)+r*u(j+1);
    end
end
u