pwSetFitLimitsAroundTrueValues(factor) Sets the limits of the currently fitted parameters k, x0, and s around the true values. This is only possible for simulated data.
factor: If 10 (default), the fit limits will be [parTrue/10 parTrue*10]
In general:
lower limit: parTrue / factor
upper limit: parTrue * factor
Temporarily fixed parameters are untouched.