Function "ismember" in Simulink?

Dear community,

I would like to know if there is a way to get a function like "ismember" to work in Simulink? In my program I have to find same points in an array. I have tried to create a workaround myself:

function index = find_same_points( A , B )

    %create empty matrix
    index_matrix = zeros(size(A,1), 3);

    %comepare each row from one martix with the other
    for i = 1 : size(A,1)    
        for j = 1 : size(B,1)

            index_matrix(i,j) =  A(i,1) == B(j,1)...
                               & A(i,2) == B(j,2)...
                               & A(i,3) == B(j,3);

        end    
    end

index =  any(index_matrix,2) ;

end

It always gives me the following error:

Runtime error: Index into array out of range Model Name: function_tester Block Name: function_tester/MATLAB Function Attempted to access 4 element of data index_matrix. The valid index range is 1 to 3 Please note that the simulation will be aborted immediately after you continue from this breakpoint to avoid segmentation violations.

Unfortunately I have no idea how to fix this... Please help!!!!