How to manipulate multidimensional numpy array in python

Question

I am new with array in python, please help me.

I have a multidimensional numpy array like this:

array([[   0., 2073., 2352., 1119., 2074., 1344., 4035., 1980., 2213.,
        2363., 2655., 2322., 1148., 2046., 2234., 1076., 1647., 2957.,
        1968., 2246., 1723.],
       [1517.,    0.,  891., 1537., 1993., 2231., 2574.,  689., 1561.,
        2157., 1517., 3275., 1566.,  757.,  774., 2190.,  822., 1355.,
        2152., 1575., 1064.],
       [1597., 1329.,    0., 1617., 1106., 1345., 1951., 1551., 1938.,
        1270.,  629., 2320., 1646., 1619.,  862., 2267., 1357.,  934.,
        1264.,  687.,  342.]])

I want to add 0 at the beginning in every array, and at the end i want to add 22 of 0 of array so it becomes like this:

array([[0.,   0., 2073., 2352., 1119., 2074., 1344., 4035., 1980., 2213.,
        2363., 2655., 2322., 1148., 2046., 2234., 1076., 1647., 2957.,
        1968., 2246., 1723.],
       [0.,1517.,    0.,  891., 1537., 1993., 2231., 2574.,  689., 1561.,
        2157., 1517., 3275., 1566.,  757.,  774., 2190.,  822., 1355.,
        2152., 1575., 1064.],
       [0.,1597., 1329.,    0., 1617., 1106., 1345., 1951., 1551., 1938.,
        1270.,  629., 2320., 1646., 1619.,  862., 2267., 1357.,  934.,
        1264.,  687.,  342.],
       [0.,0., 0., 0., 0., 0., 0., 0., 0., 0.,
        0., 0., 0., 0., 0,  0., 0, 0., 0.,
        0., 0.,    0.]])

please help me to code this

bb1 · Accepted Answer · 2022-01-14 03:28:58Z

2

If the array is arr then you can use:

np.pad(arr, ((0, 1), (1, 0)))

answered Jan 14, 2022 at 3:28

bb1

7,9232 gold badges11 silver badges26 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

RamaH Over a year ago

thanks for your answer, it works! sorry i wanna ask an out of topic question abouot the array above, do u know how to change the position of the array? i want to switch the arr[0] with arr[2] thanks

bb1 Over a year ago

Do you mean you want to interchange these two rows? If so, then arr[[0, 2]] = arr[[2, 0]] should do it.

arshovon · Accepted Answer · 2022-01-14 03:33:54Z

You can insert 0 at the beginning of every array and then append a list of 22 0.

import numpy as np

data = np.array([[0., 2073., 2352., 1119., 2074., 1344., 4035., 1980., 2213.,
                  2363., 2655., 2322., 1148., 2046., 2234., 1076., 1647.,
                  2957.,
                  1968., 2246., 1723.],
                 [1517., 0., 891., 1537., 1993., 2231., 2574., 689., 1561.,
                  2157., 1517., 3275., 1566., 757., 774., 2190., 822., 1355.,
                  2152., 1575., 1064.],
                 [1597., 1329., 0., 1617., 1106., 1345., 1951., 1551., 1938.,
                  1270., 629., 2320., 1646., 1619., 862., 2267., 1357., 934.,
                  1264., 687., 342.]])

updated = np.insert(data, 0, 0, axis=1)
updated = np.append(updated, [[0] * 22], axis=0)
print(updated)

Output:

[[   0.    0. 2073. 2352. 1119. 2074. 1344. 4035. 1980. 2213. 2363. 2655.
  2322. 1148. 2046. 2234. 1076. 1647. 2957. 1968. 2246. 1723.]
 [   0. 1517.    0.  891. 1537. 1993. 2231. 2574.  689. 1561. 2157. 1517.
  3275. 1566.  757.  774. 2190.  822. 1355. 2152. 1575. 1064.]
 [   0. 1597. 1329.    0. 1617. 1106. 1345. 1951. 1551. 1938. 1270.  629.
  2320. 1646. 1619.  862. 2267. 1357.  934. 1264.  687.  342.]
 [   0.    0.    0.    0.    0.    0.    0.    0.    0.    0.    0.    0.
     0.    0.    0.    0.    0.    0.    0.    0.    0.    0.]]

Explanation:

We have inserted in axis 1 to add 0 in the existing multidimensional array.
We have appended the list of 22 0's to axis 0 at the end.

References:

Collectives™ on Stack Overflow

How to manipulate multidimensional numpy array in python

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related