I use GenOPT coupled with Dymola to identify parameters for a thermal collector. As a result as per the GenOPT manual, the program approximates a function similar to the objective function optimises and does parameter identification.

Question1 : Do I have control over the error of approximation in dymola.

Question2 : Since I was using GPS implementation of Hookes Jeeves algorithm, I was getting identifes parameters, but it gives different minima points for different step lengths. I guess this is because of the nature of the algorithm and objective function.Solution?answers every time. Is it giving near optimal answers.