1 #!/usr/bin/python

     2 # Produces two polynomial matrices P1, P2

     3 # P1 consists of first p1 columns of P

     4 # P2 consists of remaining p2 columns of P

     5 

     6 import pylab as pl

     7 from polyfuncs import polsize

     8 

     9 def colsplit(P, degP, p1, p2):

    10     P = pl.atleast_2d(P)

    11     if pl.atleast_2d(P).size is 0:

    12         P1 = pl.atleast_2d([])

    13         P2 = pl.atleast_2d([])

    14         return P1, None, P2, None

    15 

    16     rP, cP = polsize(P, degP)

    17 

    18     if not 0 <= p1 <= cP or not 0 <= p2 <= cP or p1+p2 != cP:

    19         print 'colsplit: Inconsistent numbers of columns'

    20         return None

    21         exit(1)

    22     

    23     P1 = pl.atleast_2d(pl.zeros((rP, (degP+1)*p1)))

    24     P2 = pl.atleast_2d(pl.zeros((rP, (degP+1)*p2)))

    25     

    26     

    27     for i in range(degP+1):

    28         P1[:,i*p1:(i+1)*p1] = P[:,i*cP:i*cP+p1]

    29         P2[:,i*p2:(i+1)*p2] = P[:,i*cP+p1:(i+1)*cP]

    30     

    31     return P1, degP, P2, degP

    32 

    33 if __name__== "__main__":

    34     s = """P = pl.array([[1, 2, 3, 4, 1, 2, 3, 4],

    35            [9, 10, 11, 12, 9, 10, 11, 12],

    36            [5, 6, 7, 8, 5, 6, 7, 8]])"""

    37     print s

    38     exec(s)

    39     print """colsplit(P, 3, 1, 1)"""

    40     print colsplit(P, 3, 1, 1)