randtest.py 文件源码

def longestrunones8(binin):
    ''' The focus of the test is the longest run of ones within M-bit blocks. The purpose of this test is to determine whether the length of the longest run of ones within the tested sequence is consistent with the length of the longest run of ones that would be expected in a random sequence. Note that an irregularity in the expected length of the longest run of ones implies that there is also an irregularity in the expected length of the longest run of zeroes. Long runs of zeroes were not evaluated separately due to a concern about statistical independence among the tests.'''
    m = 8
    k = 3
    pik = [0.2148, 0.3672, 0.2305, 0.1875]
    blocks = [binin[xs*m:m+xs*m:] for xs in xrange(len(binin) / m)]
    n = len(blocks)
    counts1 = [xs+'01' for xs in blocks] # append the string 01 to guarantee the length of 1
    counts = [xs.replace('0',' ').split() for xs in counts1] # split into all parts
    counts2 = [map(len, xx) for xx in counts]
    counts4 = [(4 if xx > 4 else xx) for xx in map(max,counts2)]
    freqs = [counts4.count(spi) for spi in [1, 2, 3, 4]]
    chisqr1 = [(freqs[xx]-n*pik[xx])**2/(n*pik[xx]) for xx in xrange(4)]
    chisqr = reduce(su, chisqr1)
    pval = spc.gammaincc(k / 2.0, chisqr / 2.0)
    return pval