scipy.stats.mstats.hmean

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

Calculate the harmonic mean along the specified axis.

That is: n / (1/x1 + 1/x2 + … + 1/xn)

Parameters

aarray_like

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

axisint or None, optional

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

dtypedtype, 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.

Returns

hmeanndarray

see dtype parameter above

See also

numpy.mean

Arithmetic average

numpy.average

Weighted average

gmean

Geometric mean

Notes

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.

Examples

>>> from scipy.stats import hmean
>>> hmean([1, 4])
1.6000000000000001
>>> hmean([1, 2, 3, 4, 5, 6, 7])
2.6997245179063363