function [x,U] = pdeproblem(N,T) dx = (1-0)/N; x = dx*[0:N]; dt = dx*dx/2.0; U(1,:) = cos(2*pi*x); for n = 1:T, U(n+1,2:N) = U(n,2:N)+dt*(U(n,3:N+1)-2*U(n,2:N)+U(n,1:N-1))/(dx*dx); U(n+1,1) = 1; U(n+1,N+1) = 1; end