用于3D数组的numpy.tile

Question

I have to get 3D array demension (4, 2, 1) from two value (60, 80)

import numpy as np
array([[[ 60.],
        [ 60.]],
   [[ 60.],
    [ 60.]],
   [[ 80.],
    [ 80.]],
   [[ 80.],
    [ 80.]]])

I do as below

a = np.array([[[ 60.]],
       [[ 80.]]])
np.tile(a, (2, 2,1))

and get

array([[[ 60.],
        [ 60.]],
       [[ 80.],
        [ 80.]],
       [[ 60.],
        [ 60.]],
       [[ 80.],
        [ 80.]]])

How to get the expected array?

Answer 1

You might use combined np.tile with np.repeat :

a = np.array([[[ 60.]],
       [[ 80.]]])
np.repeat(np.tile(a, (1,2,1)), 2, axis=0)

#array([[[ 60.],
#        [ 60.]],

#       [[ 60.],
#        [ 60.]],

#       [[ 80.],
#        [ 80.]],

#       [[ 80.],
#        [ 80.]]])

Or use np.repeat + reshape :

np.repeat(a, 4).reshape(4,2,1)
#array([[[ 60.],
#        [ 60.]],

#       [[ 60.],
#        [ 60.]],

#       [[ 80.],
#        [ 80.]],

#       [[ 80.],
#        [ 80.]]])