Replacing values in a matrix

For a very large matrix of (1500000, 6) I wish to change the first 10 values in column 1 to 1, the next 10 values to 2, the next 10 to 3, etc.

Using for example:

X = randi([0,1],[1500000,6]);

To create the table.

Answer 1

[Tommy]

Try this:

N = 1500000;
X = randi([0,1],[N,6]);
i = 1:N/10;
X(:,1) = repelem(i,10);

[RickJ]

That's it! Incredible, thank you so much!!!