Fitting 2D histograms with integral fit option

ROOT
1

Hi,

I want to fit a TH2D histogram with the fits integral option, so that insteat of the bin’s center value the bin’s 2D integral is used (as for 1D histograms).
The fit works using the bin center value, i.e. ‘VERMLL’ – but when I add the integral option, i.e. ‘VERMLLI’ Root/Minuit die in a loop

...
Warning in <ROOT::Math::AdaptiveIntegratorMultiDim::Integral>: Wrong function dimension; n = 1
Warning in <ROOT::Math::AdaptiveIntegratorMultiDim::Integral>: Wrong function dimension; n = 1
...

Apparently, there is a some problem with the dimension but I have no idea if it is my fault or how I could fix it. Maybe somebody has an idea for me?

Cheers & Thanks,
Thomas

2

Hi,
which ROOT version are you using ? I think there was a problem with some old version, but it should be fixed now in 5.26

Lorenzo

3

OK, I will test it in ROOT 5.26 – at the moment I am stlll using Root 5.24

4

Fitting with option ‘I’ works with ROOT 5.26 :slight_smile:

Many thanks – Thomas