[Numpy-discussion] 2D Arrays column operations
Simon Berube
sberub@gmail....
Thu Mar 29 14:43:03 CDT 2007
Hi,
I am relatively new to Python/NumPy switching over from Matlab and
while porting some of my matlab code for practice I ran into the
following problem.
Assume we have a 2D Matrix such that
a = array([[1, 2, 3],
[4, 5, 6],
[7, 8, 9]])
If I want the second row I can simply enough take
c = a[1]
However, I would like to do a similar operation on the columns of the
2D Array. In matlab I could simply do
c = a(:,2) to get the values array([2,5,8])
In numPy this seems to not be a valid operation. I understand that
since numPy arrays are more akin to C pointer this cannot be done as
easily so my question is; what is the best way to go around obtaining
the column information I want the "numPy" way? I could simply take a
transpose and get the information this way but this seems wasteful.
More information about the Numpy-discussion
mailing list