Create Array Map or get all indices of the given 2D matrix

Hi everyone,

Let say I have two array a and b. Let a = [1 2 3], b = [4 5 6]; I want to get C= [1 1 1 2 2 2 3 3 3 4 4 4;4 5 6 4 5 6 4 5 6].

In short, I want indices of given 2D matrix.

[Jan]

Your C has 12 elements in the first row and 9 in the 2nd. This means, that it is not a valid matrix at all. In addition it is not clear, what "indices of given 2D matrix" means.

Please explain the relation between the inputs and outputs and post a valid example of the output.

It is not clear, why you set the tag "crossproduct".

Is this a homework question?