Concatenating 3 multidimensional arrays in Python-CodePudding

I have three arrays I1,I2,I3 with shape (1,9,2). I am trying to append but there is an error. The new array should have shape (3,9,2)

import numpy as np

I1 = np.array([[[0, 2],
        [2, 3],
        [2, 5],
        [3, 4],
        [3, 6],
        [4, 1],
        [4, 7],
        [5, 6],
        [6, 7]]])

I2 = np.array([[[1, 1],
        [2, 3],
        [2, 5],
        [3, 4],
        [3, 6],
        [4, 1],
        [4, 7],
        [5, 6],
        [6, 7]]])

I3 = np.array([[[2, 2],
        [2, 3],
        [2, 5],
        [3, 4],
        [3, 6],
        [4, 1],
        [4, 7],
        [5, 6],
        [6, 7]]])

I=np.append(I1,I2,I3,axis=0)

The error is

in <module>
    Iit=np.append(Iit1,Iit2,Iit3,axis=0)

  File "<__array_function__ internals>", line 4, in append

TypeError: _append_dispatcher() got multiple values for argument 'axis'

CodePudding user response：

Use I=np.concatenate([I1,I2,I3],axis=0) rather than append. Append does what you'd expect from a list (and try not to use it in numpy, anyway, for memory allocation reasons!)`

CodePudding user response：

A different way from @Dominik is

I = np.stack((I1,I2,I3))

stack creates a new axis.