[Numpy-discussion] Multiplying every 3 elements by a vector?
Charles R Harris
charlesr.harris@gmail....
Wed Jul 9 14:26:01 CDT 2008
On Wed, Jul 9, 2008 at 1:16 PM, Marlin Rowley <marlin_rowley@hotmail.com>
wrote:
> All:
>
> I'm trying to take a constant vector:
>
> v = (0.122169, 0.61516, 0.262671)
>
> and multiply those values by every 3 components in an array of length N:
>
> A = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ....]
>
> So what I want is:
>
> v[0]*A[0]
> v[1]*A[1]
> v[2]*A[2]
> v[0]*A[3]
> v[1]*A[4]
> v[2]*A[5]
> v[0]*A[6]
>
> ...
>
> How do I do this with one command in numPy?
>
>
If the length of A is divisible by 3:
A.reshape((-1,3))*v
You might want to reshape the result to 1-D.
Chuck
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://projects.scipy.org/pipermail/numpy-discussion/attachments/20080709/8631ba1d/attachment-0001.html
More information about the Numpy-discussion
mailing list