variable input in simulink function block inside stateflow chart

I am encountering a problem as, I want to plot equation of line in stateflow using simulink function block as a result of multiple inputs. For this purpose I have further used fcn block inside simulink function block to define line equation as shown in attached picture. Here I want this block to access multiple inputs (u) in the form of vector but it takes just first value and prints a dot

[Khush Bakhat Sawaiba]

here I have just shown input u instead of line equation in block