Which way are rows and columns in a numpy 2-d array used as a matrix?

Question

When using a numpy array as a matrix, in which order are rows and columns?

For example:

array([[1, 2, 3],
       [4, 5, 6],
       [7, 8, 9]])

Is [1, 2, 3] the first row or the first column?

I cannot find this information in the documentation, perhaps because the answer is too obvious.

henrywongkk · Accepted Answer · 2019-10-23 07:26:30Z

1

[1, 2, 3] is the first row.

The examples in numpy ndarray documentation actually gives you some hints:

>>> x = np.array([[1, 2, 3], [4, 5, 6]], np.int32)

>>> # The element of x in the *second* row, *third* column, namely, 6.
>>> x[1, 2] ```

answered Oct 23, 2019 at 7:26

henrywongkk

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