# Does NonlinearModelFit result stores FitResiduals? [closed]

I fits a long data series with a complex model by NonlinearModelFit:

fitnlm = NonlinearModelFit[...]


Then I can use fitnlm["BestFitParameters"] to get parameters, use fitnlm["Response"] to view original data. By the way, Length@fitnlm["Response"] gives 3603 so it is not a very long data series. However, when I try to run

fitnlm["FitResiduals"]


It seems that the mathematica core keeps running forever and didn't return an answer. The fitnlm["FitResiduals"] should have same Length as fitnlm["Response"]. Is it because that FitResiduals is not stored in fitnlm and will be calculated every time I run fitnlm["FitResiduals"]? But calculating FitResiduals should not be more difficult than run fitnlm = NonlinearModelFit[...], the later takes several seconds while the former takes forever, what's wrong?

• This can't be answered without a complete minimal example. – Szabolcs Feb 1 at 9:35