How can I use matrix using MATLAB function ina simulink?

In my simulink file, there is MATLAB fucntion.

First line of MATLAB function is below:

function Temp =fcn(a,b,c,...,T0)

Temp and T0 is matrix.

Temp(x,y) = f1(a,b,c) and T0(x,y) is a feedback of Temp.

A method that set x,y, and caculate T(x,y) is decribed in fucntion body.

If I execute this file, there is an error msg because of variable T.

Data 'T' is inferred as a variable size matrix, while its specified type is something else

But if I change T --> T(x,y) a syntax error occurs.

function Temp(x,y) =fcn(a,b,c,...,T0(x,y))

I already refer varargin and varargout, but error occurs.(varagin cannot be use first line.)

How can I do?