[Numpy-discussion] simple reduction question
ndbecker2 at gmail.com
Wed Dec 24 10:25:19 EST 2014
What would be the most efficient way to compute:
c[j] = \sum_i (a[i] * b[i,j])
where a[i] is a 1-d vector, b[i,j] is a 2-d array?
This seems to be one way:
import numpy as np
a = np.arange (3)
b = np.arange (12).reshape (3,4)
c = np.dot (a, b).sum()
but np.dot returns a vector, which then needs further reduction. Don't know if
there's a better way.
-- Those who don't understand recursion are doomed to repeat it
More information about the NumPy-Discussion