Pick a random column according to specific class data

I have matrix lets say

1 1 2 2 3 3 4 4

5 8 3 7 2 8 3 9

4 6 8 2 3 4 6 7

2 3 6 7 3 4 6 8

I want to randomly pick columns from each first row class [1 2 3 4]

Answer 1

[Image Analyst]

Try randi

A = [...
    1 1 2 2 3 3 4 4
    5 8 3 7 2 8 3 9
    4 6 8 2 3 4 6 7
    2 3 6 7 3 4 6 8];
[rows, columns] = size(A);
% Get random column indexes
randomColumns = randi(columns, rows, 1)

randomColumns = 4×1

2 1 5 7

% Get values of A there
randomValues = zeros(rows, 1);
for row = 1 : rows
    randomValues(row) = A(row, randomColumns(row));
end
randomValues

randomValues = 4×1

1 5 3 6

[Yousif Alaraji]

Many thanks,

but can I get one column from each specified Number

1 1 2 2 3 3 4 4

I have these classified columns and I just want random

1 2 3 4

[Image Analyst]

Not sure what you're asking. I thought I answered it but maybe you want unique.