tests

from random import randrange

l = 10
t = 50000

def shuffle_from_pos(arr):
    for i in xrange(l):
        j = randrange(i, l)
        arr[i], arr[j] = arr[j], arr[i]
    return arr

# copy pased from:
# http://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle#Sattolo.27s_algorithm
def sattoloCycle(items):
    i = len(items)
    while i > 1:
        i = i - 1
        j = randrange(i)  # 0 <= j <= i-1
        items[j], items[i] = items[i], items[j]
    return items

def test(f):
    rv = [0]*l
    for i in xrange(t):
        rv = map(sum, zip(rv, f(range(l))))
    return rv

def normalize(arr):
    s = float(sum(arr))
    return map(lambda a: "%.4f" % (a/s), arr)

print "each element can be moved to places after it or stay still"
print normalize(test(shuffle_from_pos))
print "Sattolo's algorithm, copy pasted from wiki"
print normalize(test(sattoloCycle))