How to divide matrix elements by corresponding matrix row sum in numpy? [duplicate]

Question

For example,

M= [[1,2], [7,8]]

then I want

[[1/3, 2/3], [7/15, 8/15]]

I'm trying to do this vectorized. One idea I have is to write s = np.sum(M, axis=1); this gives us the corresponding row sums. Then I could maybe transpose s, and copy it along the columns, then do an elementwise division of M/s, but even this seems too hacky. What's the right way?

fferri · Accepted Answer · 2015-06-25 13:24:24Z

0

Use tile to repeat it along the dimension on which sum operated.

M / np.tile(np.sum(M, 1), (1, M.shape[1]))

edited Jun 25, 2015 at 13:24

answered Jun 25, 2015 at 13:12

fferri

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