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import unittest
from itertools import pairwise
from collections import Counter
from statistics import fmean
from random import sample
class RandomSampleTests(unittest.TestCase):
def test_mean(self):
# python sample.py 100_000 100 20 0 45.5 49.5 100
M = 100_000 # number of trails
N = 100 # population size
K = 20 # sample size
C = Counter()
ranges = [0.0, 45.5, 49.5, 100.0]
for _ in range(M):
x = fmean(sample(range(N), K))
for i, (x1, x2) in enumerate(pairwise(ranges)):
if x1 <= x < x2:
C[i] += 1
self.assertEqual(C.total(), M)
self.assertTrue(abs(C[0] - 24_529) <= 1_361) # p = 0.245291
self.assertTrue(abs(C[1] - 25_471) <= 1_378) # p = 0.254709
self.assertTrue(abs(C[2] - 50_000) <= 1_581) # p = 0.500000
if __name__ == '__main__':
unittest.main()
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