Python: Statistics

By Xah Lee. Date: .

use the bundled lib for statistics. https://docs.python.org/3/library/statistics.html 

from statistics import *
from math import factorial, sqrt

xdata = [9, 7, 2, 3.2, 808]

def xah_mean(xlist):
    """arithmetic mean"""
    return sum(xlist)/len(xlist)

def xah_pstdev(xlist):
    """population standard deviation"""
    mm = mean(xlist)
    return sqrt(sum([(x - mm) **2 for x in xlist])/len(xlist) )

def xah_stdev(xlist):
    """sample standard deviation"""
    mm = mean(xlist)
    return sqrt(sum([(x - mm) **2 for x in xlist])/(len(xlist) -1) )

print( "arithmetic mean is", mean(xdata), fmean(xdata) , xah_mean(xdata))

print( "population standard deviation", pstdev(xdata), xah_pstdev(xdata))

print( "sample standard deviation", stdev(xdata), xah_stdev(xdata))

Python, Statistics, Probability