import math


def untemper(interval, div=12):
    """
    Converts a tempered interval into a frequency ratio.

    Parameters
    ----------
    interval : int | float
        The interval to convert. The value can be an integer, float,
        or a list of the same.
    div : int
        The divisions per octave. 12 will convert from
        semitones and 1200 will convert from cents.
    Returns
    -------
    The untempered frequency ratio
    """

    func = lambda i,d: math.pow(2.0, i/d)
    if type(interval) is list:
        return [func(i, div) for i in interval]
    return func(interval, div)