How to divide 3-5 group dataset?

Hello, my project is about sign recognition. My dataset will about 50 images for each 26 alphabet. I want to divide it to be 3 or 5 group. Can you advice me how to do it? Thank you.

Answer 1

[KSSV]

Decide the number of elements in each group.

G1 = 10; G2 = 10 ; G3 = 30 ;   % three groups 
N = 50 ;  % 50 images 
idx = 1:N ;

C1 = randsample(idx,G1) ;  % group 1
idx = setdiff(idx,C1) ;
C2 = randsample(idx,G2) ;  % group 2 
C3 = setdiff(idx,C2) ;

[yuto nonoa]

thank you sir