Re: fitting problem

Hi Roger,

you can try to increase the maximum number of function calls, with:

TVirtualFitter::SetMaxIterations(n) with a large n (maybe 50 or 100k).

However, I doubt this will actually work. I guess you need to help the minimization by giving initial parameters closer to the minimum. I could help you, if you send me a macro with your fitting code (graph + fitting function)

  Cheers

  Lorenzo
On Feb 9, 2007, at 4:22 PM, Roger Mason wrote:

> Hello rooters,
>
> I'm trying to fit a TGraph of 2775 points generated by combination
> of 4 gaussians +
> noise. The fit does not converge:
>
> root [1] **********
> ** 5 **MIGRAD 5000 0.002775
> **********
> CALL LIMIT EXCEEDED IN MIGRAD.
> MIGRAD TERMINATED WITHOUT CONVERGENCE.
> FCN=1328.43 FROM MIGRAD STATUS=CALL LIMIT 11189 CALLS
> 11190 TOTAL
> EDM= unknown STRATEGY= 1 NO ERROR
> MATRIX
>
>
>
> A fit to a similar spectrum with only 3 gaussians converges OK.
>
> What do I need to tweak to get this to work?
>
> Thanks,
> Roger
>
Received on Fri Feb 09 2007 - 16:56:25 CET