Hi all.

I’m fitting an invariant mass with a TF1 with 10 variables… and I use 5 from those to draw my background…

I want to user IntegralError to the background function, but since I don’t fit with it, I cannot, unless I provide it with the cov matrix (I think)…

What I’ve done so far is

TVirtualFitter *fitter = TVirtualFitter::GetFitter();
double * covMatrix = fitter->GetCovarianceMatrix();
float a = background->IntegralError(0, 10, background->GetParameters(), covMatrix, 0.0000001);

But it doesn’t work… Any help would be grateful…

Many thanks,

Hi Stephanos,

Did you resolve/work around your issue?