How do I extract a set of given columns from a numPy array?

Question

Given a numpy array such as:

x = array([[0,  1,  2,  3],
          [ 4,  5,  6,  7],
          [ 8,  9, 10, 11],
          [12, 13, 14, 15]])

How do I form a new array composed of the first and third columns?

user401247 · Accepted Answer · 2013-12-20 06:20:08Z

2

To extract the first and third columns from the array use the following syntax:

x[:,[0,2]]

This means, take all rows, selecting only columns 0 and 2. Note that indexing in numPy arrays starts at zero.

answered Dec 20, 2013 at 6:20

user401247

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