Covariance matrix

Hi all.

I need help on the following…

I’m fitting with a combination of functions, e.g. linear+gaussian. But I want to get the IntegralError of one of the functions (either the linear or the gaussian).

So I think I have to get the covariance matrix

TVirtualFitter *fitter = TVirtualFitter::GetFitter();
double * covMatrix = fitter->GetCovarianceMatrix();

and then distinguish in there the part that corresponds to the function I want?

Many thanks in advance…