将 2D 数组附加到 3D 数组，扩展第三维

Question

I have an array A that has shape (480, 640, 3) , and an array B with shape (480, 640) .

How can I append these two as one array with shape (480, 640, 4) ?

I tried np.append(A,B) but it doesn't keep the dimension, while the axis option causes the ValueError: all the input arrays must have same number of dimensions .

Answer 1

Use dstack :

>>> np.dstack((A, B)).shape
(480, 640, 4)

This handles the cases where the arrays have different numbers of dimensions and stacks the arrays along the third axis.

Otherwise, to use append or concatenate , you'll have to make B three dimensional yourself and specify the axis you want to join them on:

>>> np.append(A, np.atleast_3d(B), axis=2).shape
(480, 640, 4)

Answer 2

使用np.stack应该可以工作，但问题是两个数组都应该是 2D 形式。

np.stack([A,B])