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

# linearly approximate a functions derivative in an interval
def linear_approximate(interval, function):
    return (function(interval[1]) - function(interval[0])) / (interval[1] - interval[0])


# function to linearly approximate
def f(x):
    return 3 + x * x - 5 * x


def test():
    print("linear approximation: ", linear_approximate([2.0, 3.0], f))