# Python module for approximating a zero point of any given function
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# Licensed under the GPLv2 License, Version 2.0 (the "License");
# Copyright (c) Sven Vogel

def zero_point_approximation(interval, function, iterations):
    for _ in range(iterations):
        median = interval[1] - (interval[1] - interval[0]) / 2
        if function(median) > 0:
            interval[1] = median
        else:
            interval[0] = median

    return interval


def f(x):
    return 4 * x * x * x - 7 * x * x + 5 * x - 12


def test():
    print("Zero-point approximation: ", zero_point_approximation(interval=[-9, 9], function=f, iterations=15))