Creating a new matrix from unique combinations in two other matrices

I have two matrices (A & B), each with the same dimensions. Each matrix contains values to divide my data into different bins. How do I create a third matrix (C) of the unique combinations of values in A and B, so that I can then use matrix C to get the mean values of grid points from a different variable at all indices with the same value in C.

I.E., If

A =

1 1 1 2 2 2 3 3 3

1 1 1 2 2 2 3 3 3

1 1 1 2 2 2 3 3 3

B =

1 1 1 1 1 1 1 1 1

2 2 2 2 2 2 2 2 2

3 3 3 3 3 3 3 3 3

then the 3rd matrix (C) would be:

1 1 1 2 2 2 3 3 3

4 4 4 5 5 5 6 6 6

7 7 7 8 8 8 9 9 9

How do I create C? (The actual dataset is much larger than that this)

Thanks!!!

Answer 1

[Stephen23]

[A,B] = meshgrid(repelem(1:3,3),1:3)

A = 3×9

1 1 1 2 2 2 3 3 3 1 1 1 2 2 2 3 3 3 1 1 1 2 2 2 3 3 3

B = 3×9

1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3

M = [reshape(A.',[],1),reshape(B.',[],1)];
[~,~,X] = unique(M,'rows','stable');
C = reshape(X,flip(size(A))).'

C = 3×9

1 1 1 2 2 2 3 3 3 4 4 4 5 5 5 6 6 6 7 7 7 8 8 8 9 9 9