numpy divide row by row sum

Question

How can I divide a numpy array row by the sum of all values in this row?

This is one example. But I\'m pretty sure there is a fancy and much more efficient way of do

Answer 1

You can do it mathematically as .

Here, E is your original matrix and D is a diagonal matrix where each entry is the sum of the corresponding row in E. If you're lucky enough to have an invertible D, this is a pretty mathematically convenient way to do things.

In numpy:

import numpy as np

diagonal_entries = [sum(e[row]) for row in range(e.shape[0])]
D = np.diag(diagonal_entries)
D_inv = np.linalg.inv(D)
e = np.dot(e, D_inv)