Re: Info about warning during fit

Hi,

two things.
I am using Root v5.26.00 and I don't have any function named like that. On the other hand, I have a ROOT::Math::Minimizer::SetMaxFunctionCalls(n);

which causes the macro to crash with segmentation fault.

What am I doing wrong?

Ciao

        Alberto

On 05/26/2010 11:42 AM, Lorenzo Moneta wrote:
> Hi,
>
> Minuit did not finish the minimization due to a call limit. Try to increase it by doing before fitting:
>
> ROOT::Math::Minimizer::SetDefaultMaxFunctionCalls(n);
>
> with n=10000 for example or larger if needed. The default depends on the number of parameters but is around 1350 in your case
>
> Best Regards
>
> Lorenzo
> On May 26, 2010, at 11:33 AM, Alberto Pulvirenti wrote:
>
>> Dear ROOTers,
>>
>> I tried to fit a 4-points histogram with a function, and the messages coming out from this were the following:
>>
>> Warning in<Fit>: Abnormal termination of minimization.
>> FCN=196.407 FROM MIGRAD STATUS=CALL LIMIT 1354 CALLS 1355 TOTAL
>> EDM=0.119482 STRATEGY= 1 ERROR MATRIX UNCERTAINTY 25.4 per cent
>> EXT PARAMETER APPROXIMATE STEP FIRST
>> NO. NAME VALUE ERROR SIZE DERIVATIVE
>> 1 p0 4.35504e+08 5.93416e+07 1.03921e+07 -1.89308e-07
>> 2 p1 4.81494e-03 1.32883e-04 -1.25183e-05 -1.00685e+05
>> 3 p2 6.22473e+00 3.22669e-02 3.13859e-03 2.24320e+02
>> Warning in<TBackCompFitter::GetCovarianceMatrix>: Invalid fit result
>> Error in<TF1Helper>: Fitter has no covariance matrix
>> Warning in<TBackCompFitter::GetCovarianceMatrix>: Invalid fit result
>> Error in<TF1Helper>: Fitter has no covariance matrix
>> Warning in<TBackCompFitter::GetCovarianceMatrix>: Invalid fit result
>> Error in<TF1Helper>: Fitter has no covariance matrix
>> Warning in<TBackCompFitter::GetCovarianceMatrix>: Invalid fit result
>> Error in<TF1Helper>: Fitter has no covariance matrix
>> Warning in<TBackCompFitter::GetCovarianceMatrix>: Invalid fit result
>> Error in<TF1Helper>: Fitter has no covariance matrix
>>
>>
>> The last errors were due probably to my attempt to compute the integral error, which probably fails due to this "abnormal termination" of the fit.
>> How can I check what's wrong with the fit and how I can get rid of that?
>>
>> Thanks, cheers
>>
>> Alberto
>>
>
Received on Wed May 26 2010 - 11:51:50 CEST