Timeline for Troubles in FindFit and NMinimize with NIntegrate
Current License: CC BY-SA 3.0
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 7, 2017 at 19:39 | answer | added | JimB | timeline score: 1 | |
| Aug 7, 2017 at 13:39 | comment | added | JimB | Looking at the predictions using the starting values suggests that whatever parameters influence the amplitude and phase need changing: predicted = Table[{dat1[[i, 1]], F[10^-3, 0.5, (dat1[[i, 1]] + 3.5), a, b, c, d] /. {a -> 10^-4, b -> 10^-5, c -> 10^-5, d -> 0.1}}, {i, Length[dat1]}]; ListPlot[{dat1, predicted}]. | |
| Aug 7, 2017 at 11:38 | comment | added | Michael E2 | slwcon is not an error message. It's a warning. Do you get other messages? -- The warning is probably because the integrand is oscillatory and the ?NumericQ in FL[] prevents symbolic analysis. Given that it's necessary b/c of FindRoot, I don't know what to suggest at the moment. You might be able to use NIntegrate`LevinIntegrandReduce (look up in the NIntegrate Rules tutorial in thedocs) on the formula at the end of FL. Since x depends on R and you have Sin[x] etc. in the integrand, it may not be helpful. | |
| Aug 7, 2017 at 9:45 | history | asked | Hsin | CC BY-SA 3.0 |