x = linspace(0, 1, 10);
psi_0 = sin(2 * pi * x);
psi_0_02 = exp(-4*pi*pi*(1/6)*0.02) * sin(2*pi*x);
psi_50 = iterate(psi_0, psi_0_02, 1/9, 0.02, 2501, [3, 5, 45, 2500]);