[FEAT] Statistics for measures of spread

[manel1874]

Request new nada-numpy feature

Implement the following statistical functionalities for measures of spread, modelled after the Python statistics module:

• Population standard deviation
• Population variance
• Sample standard deviation

Description

The new features should be integrated into the nada-numpy library and should operate on one NadaArray object. The functionalities should be defined as follows:

• pstd(): Calculate and return the population standard deviation of one NadaArray objects.
• pvar():: Compute and return the population variance of one NadaArray objects.
• std(): Calculate and return the sample standard deviation of one NadaArray objects.

Reference material

• Python statistics
• Numpy statistics