Question

I have this function

f(a,b) = { 
            a*a/b   if a < b,
            b       if a >= b 
         }

defined for values of a and b between 0 and 1 inclusive.

The function is continuous at all valid values of a and b in this range. (Really! try it yourself!) But I’m not sure how to evaluate it in Simulink. The problem is that I can’t figure out how to restate it in a way that I could evaluate both “forks” of the function and take the min or max (e.g. min(a*a,b*b)/b) without having a divide-by-zero error at b=0, and I’d like to avoid getting into things like conditionally-executed subsystems.

Does anyone know how I might go about doing this?

Answer 1

You have some strange constraints. Since you insist on evaluating both forks and taking the min of the two, the only solution is to not divide by zero but by a small enough number to avoid an error (eps for instance).

or with if action blocks: