X = zeros(31,31);
Xbound = zeros(31,31);

X(1:31,1) = 0;
Xbound(1:31,1) = 1;

X(1,10:15) = -10; 
Xbound(1,10:15) = 1; 

X(15:20,15:19) = 6;
Xbound(15:20,15:19) = 1;

L = Laplace(X,Xbound,200,1,0.1);
surf(L);
xlabel('x');
ylabel('y');
zlabel('potential');
title('Example of solution of the Poisson equation')

