1 #!/usr/bin/python

     2 # given A and B arrays, returns C = [<-A-> 0

     3 #                                    0  <-B->] with B shifted east by N cols

     4 

     5 import pylab as pl

     6 from scipy import signal

     7 

     8 def seshft(A, B, N):

     9     Arows, Acols = pl.atleast_2d(A).shape

    10     Brows, Bcols = pl.atleast_2d(B).shape

    11 

    12     if N>=0:

    13         n = Arows+Brows

    14         m = max(Acols, Bcols+N)

    15         C = pl.zeros((n, m))

    16         C[:Arows, :Acols] = A

    17         C[Arows:, N:N+Bcols] = B

    18 

    19     else:

    20         N = -N

    21         n = Arows+Brows

    22         m = max(Acols+N, Bcols)

    23         C = pl.zeros((n, m))

    24         C[:Arows, N:N+Arows] = A

    25         C[Arows:, :Bcols] = B

    26 

    27     return C

    28 

    29 if __name__== "__main__":

    30     a = "A = pl.eye(3)"

    31     b = "B = pl.eye(10)"

    32     n = "N = 0"

    33     exec(a)

    34     exec(b)

    35     exec(n)

    36     print a, b, n

    37     C = seshft(A, B, N)

    38     print C