Function geometric_mean

Lib/statistics.py:224–261

Convert data to floats and compute the geometric mean. Raises a StatisticsError if the input dataset is empty or if it contains a negative value. Returns zero if the product of inputs is zero. No special efforts are made to achieve exact results. (However, this may change in t

(data)

def geometric_mean(data):
    """Convert data to floats and compute the geometric mean.

    Raises a StatisticsError if the input dataset is empty
    or if it contains a negative value.

    Returns zero if the product of inputs is zero.

    No special efforts are made to achieve exact results.
    (However, this may change in the future.)

    >>> round(geometric_mean([54, 24, 36]), 9)
    36.0

    """
    n = 0
    found_zero = False

    def count_positive(iterable):
        nonlocal n, found_zero
        for n, x in enumerate(iterable, start=1):
            if x > 0.0 or math.isnan(x):
                yield x
            elif x == 0.0:
                found_zero = True
            else:
                raise StatisticsError('No negative inputs allowed', x)

    total = fsum(map(log, count_positive(data)))

    if not n:
        raise StatisticsError('Must have a non-empty dataset')
    if math.isnan(total):
        return math.nan
    if found_zero:
        return math.nan if total == math.inf else 0.0

    return exp(total / n)


def harmonic_mean(data, weights=None):