Storing "n" number of 2D matrices into a single 3D matrix

Question

I have "n" number of 2D matrices of same size. I want to store all these 2D matrices one by one into a single 3D numpy matrix/array.

Can anyone please tell me how to do this in python?

Have you tried to look by yourself before posting here? There's plenty of ways to do it, this question clearly doesn't show enough research effort. — RandomGuy, May 10 '21 at 15:15
@RandomGuy yes sir, I looked alot but all the methods were storing the 2 to 3 matrices. But I need a method where I would be storing a single matrix one by one into the 3d numpy array. — Saptarshee Sarkar, May 10 '21 at 15:19

Sırrı Kırımlıoğlu · Answer 1 · 2021-05-10T15:18:24.267

0

You can use numpy.dstack() such as:

import numpy as np
a = np.array([[1,2,3],[1,2,3]])
b = np.array([[2,3,4],[2,3,4]])
c = np.array([[3,4,5],[3,4,5]])
new_3d = np.dstack((a,b,c))

Output:

[[[1 2 3]
 [2 3 4]
 [3 4 5]]

[[1 2 3]
 [2 3 4]
 [3 4 5]]]

Update for new question:

Also, you can add another 2d again and again like:

d = np.array([[3,4,5],[3,4,5]])
new_3d = np.dstack((new_3d,d))

Output:

[[[1 2 3 3]
 [2 3 4 4]
 [3 4 5 5]]

 [[1 2 3 3]
 [2 3 4 4]
 [3 4 5 5]]]

edited May 10 '21 at 15:18

answered May 10 '21 at 14:43

But what if if there are 100 number of 2D matrices ?? – Saptarshee Sarkar May 10 '21 at 15:09
@SaptarsheeSarkar I updated my answer, you can check. – Sırrı Kırımlıoğlu May 10 '21 at 15:18
Got it, while using dstack , when I am iterating through the final 3d array and want to get the a,b,c, & d matrices I ain't getting them in their original form ? – Saptarshee Sarkar May 10 '21 at 15:31
@SaptarsheeSarkar will be added with their original form, but I don't exactly understand your question. Do you want to get them after the addition of the 3d matrix? – Sırrı Kırımlıoğlu May 11 '21 at 06:51

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