Re: parameter correlation coefficients by gMinuit or TVirtualFitter

HI Nevtaz,

  you can easily get the correlation coefficients from the covariance matrix:

  C(i,j) = CovarianceMatrix(i,j)/ sqrt( CovarianceMatrix(i,i) *CovarianceMatrix(j,j) );

Cheers

  Lorenzo
On Aug 27, 2007, at 8:54 PM, Nevzat Guler wrote:

>
> As far as I know GetCovarianceMatrix and
> GetCovarianceMatrixElement are to acces to error matrix. But what I
> want
> is not the error matrix. I want to acces to parameter correlation
> coefficients.
> Thanks..
>
>
> Nevzat Guler
>
> On Mon, 27 Aug 2007, Rene Brun wrote:
>
>> Use TVitualFitter::GetCovarianceMatrixElement(int i, int j).
>>
>> Rene Brun
>>
>> Nevzat Guler wrote:
>>> Hello,
>>> How can I access to parameter correlation coefficients by gMinuit
>>> or TVirtualFitter ? There is mnmatu in Minuit but I couldn't find
>>> how we
>>> call it? Best Regards..
>>> Nevzat Guler
>>>
>>> P.S. I want the parameter correlation coefficients not the
>>> covariance
>>> matrix elements from GetCovarianceMatrix()
>>> Many Thanks in advance...
>>>
>>
>>
>
Received on Tue Aug 28 2007 - 09:54:27 CEST