x = 0:0.5:12;
y = x;
[X, Y] = meshgrid(x,y);

ratkaisu = zeros(size(X));

for k=0:50
  n = 2*k + 1;
  ratkaisu = ratkaisu + sinh(n*pi*X/12) .* sin(n*pi*Y/12) ./ (n *sinh(n*pi));
end

ratkaisu = ratkaisu * 400 / pi;

surf(x,y,ratkaisu)
