# Python module for approximating the fixpoint of special linear functions
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# Licensed under the GPLv2 License, Version 2.0 (the "License");
# Copyright (c) Sven Vogel


# iteratively approximate the fixpoint of specific linear functions
def fixpoint_approximation(start, function, iterations):
    x = start
    for _ in range(iterations):
        x = function(x)

    return x


# in order to work the linear function has to be in the form:
# ]-1.0, 1.0[ * x + k
def linear_function(x):
    return 0.25 * x - 3


def test():
    print("fixpoint approximation: ", fixpoint_approximation(start=1.0, function=linear_function, iterations=400))