1 #!/usr/bin/python

     2 

     3 import pylab as pl

     4 from makezero import makezero

     5 

     6 def cindep(S, gap=None):

     7     E = pl.finfo(float).eps

     8 

     9     if gap == None:

    10         gap = 1e8

    11 

    12     r, c = pl.atleast_2d(S).shape

    13 

    14     if r>c:

    15         ind = 0

    16     else:

    17         sigma = pl.svd(S)[1]

    18         l = len(sigma)

    19         if(sigma[-1]/sigma[0] < (E*max(1, c))):

    20             ind = 0

    21         else:

    22             if pl.any(sigma[:-1]/sigma[1:] >= gap):

    23                 ind = 0

    24             else:

    25                 ind = 1

    26     if ind:

    27         b = pl.array([])

    28 

    29     else:

    30         A, B = S[r-1,:], S[:r-1,:] 

    31         b = pl.lstsq(B.T, A.T)[0].T

    32         b = makezero(b, gap)

    33         b = b.squeeze()

    34     return pl.atleast_2d(b)

    35 

    36 if __name__== "__main__":

    37     pass