If I have a matrix `matrix1`

like

```
[[80 80 80 80]
[ 0 50 0 0]
[ 0 0 50 0]
[ 0 0 0 50]
[30 30 30 30]]
```

which is shape `(5,4)`

and I do `matrix2=matrix[...,np.newaxis]`

I get a matrix with shape:

`(5,4,1)`

My question is, how can I get a matrix of shape `(5,4,n)`

with n being any number other than 1?

Source: Python Questions