Closed tmadlener closed 3 weeks ago
I think other than in the converter probability
is never used in Key4hep and others and this change makes sense. Also going from chi2
and ndf
to probability is trivial while the other way not so much. For tracks we already have ndf
.
Thinking about all the fits there is also Hyptothesis
that has chi2
but no probability nor ndf. In case these proliferate (if it's only for tracks and vertexes then maybe it's not worth it), we may want to introduce something like a FitResult
that would have chi2
and ndf
and provide some utilities to get the p value if there is a need for it.
Yeah, for Hypothesis
I am also not entirely sure what the chi2
is exactly. See also one point on this #323
I agree with the rest. I would be in favor of keeping chi2
and ndf
for now (mainly because it is less work ;) )
We (BH, JMC, FG) agree to replace probability
w/ ndf
- and suggest to not introduce a component now.
The
Vertex
currently has memberschi2
andprobability
. The much more natural choice in this case would be to havendf
instead ofprobability
, since that gives the information about the fit quality on a lower level from which higher level quantities, such asprobability
can be easily calculated.https://github.com/key4hep/EDM4hep/blob/bd9f45039149781a9c54799a6d03df56b1b5ed49/edm4hep.yaml#L551-L557