scipy.stats.mstats.hmean(a, axis=0, dtype=None)[source]

Calculates the harmonic mean along the specified axis.

That is: n / (1/x1 + 1/x2 + ... + 1/xn)


a : array_like

Input array, masked array or object that can be converted to an array.

axis : int or None, optional

Axis along which the harmonic mean is computed. Default is 0. If None, compute over the whole array a.

dtype : dtype, optional

Type of the returned array and of the accumulator in which the elements are summed. If dtype is not specified, it defaults to the dtype of a, unless a has an integer dtype with a precision less than that of the default platform integer. In that case, the default platform integer is used.


hmean : ndarray

see dtype parameter above

See also

Arithmetic average
Weighted average
Geometric mean


The harmonic mean is computed over a single dimension of the input array, axis=0 by default, or all values in the array if axis=None. float64 intermediate and return values are used for integer inputs.

Use masked arrays to ignore any non-finite values in the input or that arise in the calculations such as Not a Number and infinity.