[Python] how to calculate harmonic mean of numbers

Question

Is there any Python function to calculate the harmonic mean of a list of numbers?

Answer 1

You can use the hmean() function of scipy.stats. This function calculates the harmonic mean along the specified axis. i.e. n / (1/x1 + 1/x2 + … + 1/xn)

>>> from scipy.stats import hmean

>>> a=np.array([10,20,15])

>>> hmean(a)

13.846153846153845

>>> 

You can also apply this function to a 2D array.

>>> a=np.array([[1,2],[11,12],[21,22]])

>>> a

array([[ 1,  2],

       [11, 12],

       [21, 22]])

>>> hmean(a,axis=0)

array([2.63498099, 4.77108434])

>>> hmean(a,axis=1)

array([ 1.33333333, 11.47826087, 21.48837209])