diff --git a/maths/simpson_rule.py b/maths/simpson_rule.py index d66dc39a7171..e75fb557a2f5 100644 --- a/maths/simpson_rule.py +++ b/maths/simpson_rule.py @@ -1,7 +1,7 @@ """ Numerical integration or quadrature for a smooth function f with known values at x_i -This method is the classical approach of suming 'Equally Spaced Abscissas' +This method is the classical approach of summing 'Equally Spaced Abscissas' method 2: "Simpson Rule" @@ -9,9 +9,41 @@ """ -def method_2(boundary, steps): +def method_2(boundary: list[int], steps: int) -> float: # "Simpson Rule" # int(f) = delta_x/2 * (b-a)/3*(f1 + 4f2 + 2f_3 + ... + fn) + """ + Calculate the definite integral of a function using Simpson's Rule. + :param boundary: A list containing the lower and upper bounds of integration. + :param steps: The number of steps or resolution for the integration. + :return: The approximate integral value. + + >>> round(method_2([0, 2, 4], 10), 10) + 2.6666666667 + >>> round(method_2([2, 0], 10), 10) + -0.2666666667 + >>> round(method_2([-2, -1], 10), 10) + 2.172 + >>> round(method_2([0, 1], 10), 10) + 0.3333333333 + >>> round(method_2([0, 2], 10), 10) + 2.6666666667 + >>> round(method_2([0, 2], 100), 10) + 2.5621226667 + >>> round(method_2([0, 1], 1000), 10) + 0.3320026653 + >>> round(method_2([0, 2], 0), 10) + Traceback (most recent call last): + ... + ZeroDivisionError: Number of steps must be greater than zero + >>> round(method_2([0, 2], -10), 10) + Traceback (most recent call last): + ... + ZeroDivisionError: Number of steps must be greater than zero + """ + if steps <= 0: + raise ZeroDivisionError("Number of steps must be greater than zero") + h = (boundary[1] - boundary[0]) / steps a = boundary[0] b = boundary[1] @@ -41,11 +73,14 @@ def f(x): # enter your function here def main(): a = 0.0 # Lower bound of integration b = 1.0 # Upper bound of integration - steps = 10.0 # define number of steps or resolution - boundary = [a, b] # define boundary of integration + steps = 10.0 # number of steps or resolution + boundary = [a, b] # boundary of integration y = method_2(boundary, steps) print(f"y = {y}") if __name__ == "__main__": + import doctest + + doctest.testmod() main()