How to combine two matrix signals to single signal?

I have an interpreted matlab function-fcn (a,b) where the inputs (a,b) are matrices generated in the model.The function block in simulink takes only single input,but I want to pass both the matrices as an input to the function block.I am looking for a way to combine the matrices to a single signal,just like a mux block for vector signals.

Answer 1

[Explorer]

 a=[1 2 ; 3 4]; b=[5 6 ; 7 8]; ab=[a b]