Re: Info about warning during fit

From: Lorenzo Moneta <Lorenzo.Moneta_at_cern.ch>
Date: Wed, 26 May 2010 11:59:56 +0200


I am sorry, I mistyped the command, the right one is

ROOT::Math::MinimizerOptions::DefaultMaxFunctionCalls(n);

 Lorenzo
On May 26, 2010, at 11:51 AM, Alberto Pulvirenti wrote:

> 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 - 12:00:03 CEST

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