Function bisection

maths/numerical_analysis/bisection_2.py:27–54

>>> bisection(-2, 5) 3.1611328125 >>> bisection(0, 6) 3.158203125 >>> bisection(2, 3) Traceback (most recent call last): ... ValueError: Wrong space!

(a: float, b: float)

def bisection(a: float, b: float) -> float:
    """
    >>> bisection(-2, 5)
    3.1611328125
    >>> bisection(0, 6)
    3.158203125
    >>> bisection(2, 3)
    Traceback (most recent call last):
        ...
    ValueError: Wrong space!
    """
    # Bolzano theory in order to find if there is a root between a and b
    if equation(a) * equation(b) >= 0:
        raise ValueError("Wrong space!")

    c = a
    while (b - a) >= 0.01:
        # Find middle point
        c = (a + b) / 2
        # Check if middle point is root
        if equation(c) == 0.0:
            break
        # Decide the side to repeat the steps
        if equation(c) * equation(a) < 0:
            b = c
        else:
            a = c
    return c


if __name__ == "__main__":