Reshape a numpy array from [1,2,3,4] into [[1],[2],[3],[4]]

Question

I want to reshape

[1,2,3,4]

into:

[[1],[2],[3],[4]]

Is there a simple numpy method to do this?

score 3 · Answer 1 · answered Mar 31 '19 at 05:01

3

Use

reshaped_arr = arr.reshape(4,1)

Testing it out:

import numpy as np

arr = np.arange(4)
reshaped_arr = arr.reshape(4,1)
print (reshaped_arr)

Output:

[[0]
 [1]
 [2]
 [3]]

answered Mar 31 '19 at 05:01

fountainhead

@mm_ Could you elaborate your question? How exactly are you trying to use `np.linspace`, and to do what? – fountainhead Mar 31 '19 at 05:07
found my error ;-) Thanks for the answer ! – mm_ Mar 31 '19 at 05:10

score 2 · Accepted Answer · answered Mar 31 '19 at 05:03

There are a few ways. You can use the reshape method:

a = np.array([1, 2, 3, 4])
a.reshape(len(a), -1)

Or the reshape free function:

np.reshape(a, (len(a), -1))

Or np.newaxis:

a[:, np.newaxis]

All of these give the same output:

array([[1],
       [2],
       [3],
       [4]])

2 Answers2