substitue a matrix into another with some conditions

Hello

I have a matrix like:

A=[1 1;2 1;3 1;1 2;2 2;3 2;1 3;2 3;3 3]

and another B=[4 1; 5 1; 4 2; 5 2; 4 3; 5 3]

The condition for substitution is when first row array in A becomes equal to array value in B minus 1, substitute B rows whose second column values equal second column values in corresponding rows of A and so forth as can be seen in product matrix C:

C=[1 1;2 1;3 1; 4 1; 5 1; 1 2;2 2;3 2; 4 2; 5 2;1 3;2 3;3 3; 4 3; 5 3]

How should I code this?

Answer 1

[Voss]

The method below may or may not be what you have in mind. If it's not, can you provide a more general example or two?

A=[1 1;2 1;3 1;1 2;2 2;3 2;1 3;2 3;3 3];
B=[4 1; 5  1; 4 2; 5 2; 4 3; 5 3];

C = [A; B];
[~,idx] = sort(C(:,2));
C = C(idx,:);
disp(C)

     1     1
     2     1
     3     1
     4     1
     5     1
     1     2
     2     2
     3     2
     4     2
     5     2
     1     3
     2     3
     3     3
     4     3
     5     3

C_wanted=[1 1;2 1;3 1; 4 1; 5 1; 1 2;2 2;3 2; 4 2; 5 2;1 3;2 3;3 3; 4 3; 5 3];
isequal(C,C_wanted)

ans = logical
   1