def plot_max_error_graph(self, limit, IVPx, IVPy, delta):
euler_max_error_vector = []
imp_euler_max_error_vector = []
rk_max_error_vector = []
err_x_vector = []
N = int((limit - IVPx) / delta)
for i in range(1, N):
err_x_vector.append(i)
for i in range(1, N):
delta = float(float((limit - IVPx)) / i)
if delta == 0: delta = float(1)
computer = Computation(IVPx, IVPy, delta, limit)
euler_x_vector, euler_y_vector, imp_euler_x_vector, imp_euler_y_vector, \
rk_x_vector, rk_y_vector, exact_x_vector, exact_y_vector = computer.compute(delta, IVPx, IVPy, limit)
euler_error_vector, imp_euler_error_vector, rk_error_vector = computer.get_local_errors(
euler_x_vector, euler_y_vector, imp_euler_x_vector,
imp_euler_y_vector, rk_x_vector, rk_y_vector, exact_x_vector,
exact_y_vector)
print(delta, max(euler_error_vector), max(imp_euler_error_vector),
max(rk_error_vector))
euler_max_error_vector.append(max(euler_error_vector))
imp_euler_max_error_vector.append(max(imp_euler_error_vector))
rk_max_error_vector.append(max(rk_error_vector))
pyplot.figure()
pyplot.plot(err_x_vector, euler_max_error_vector, label="Euler")
pyplot.plot(err_x_vector,
imp_euler_max_error_vector,
label="Improved Euler")
pyplot.plot(err_x_vector, rk_max_error_vector, label="Runge-Kutta")
pyplot.suptitle("Error-Step size graph")
pyplot.xlabel("Step size")
pyplot.ylabel("Error")
pyplot.legend(loc="upper left")
pyplot.show()
