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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?

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