def entropy_of_antennas(positions, normalize=False):
    """
    The entropy of visited antennas.

    Parameters
    ----------
    normalize: boolean, default is False
        Returns a normalized entropy between 0 and 1.
    """
    counter = Counter(p for p in positions)
    raw_entropy = entropy(list(counter.values()))
    n = len(counter)
    if normalize and n > 1:
        return raw_entropy / math.log(n)
    else:
        return raw_entropy