Timing/profiling tests on different branches of https://github.com/wkschwartz/algorithms2

profiling.py

from math import sqrt

def ttest(x1, x2):
	"Student's t-test for unpaired, equal variance, equal size samples."
	if len(x1) != len(x2):
		raise ValueError('unequal sample sizes')
	mx1 = sum(x1) / len(x1)
	mx2 = sum(x2) / len(x2)
	s2x1 = sum((xi - mx1)**2 for xi in x1) / (len(x1) - 1)
	s2x2 = sum((xi - mx2)**2 for xi in x2) / (len(x2) - 1)
	sx1x2 = sqrt((s2x1 + s2x2) / 2)
	return (mx1 - mx2) / (sx1x2 * sqrt(2 / len(x1)))

# Time to run MoveToFront encoding->decoding on different branches on mobydick.txt
ll    = [.238, .233, .238, .218, .223, .224, .243]
array = [.266, .258, .247, .256, .250, .257, .248]

print('t-value: %s' % ttest(ll, array))
print('degrees of freedom: %s' % (2 * len(ll) - 2))
# t-value: -5.401857486891129
# degrees of freedom: 12
# This means a 99% probability that ll is faster than array