conversion Hist -> ROOT

[slehti]

In coffea, there is support for converting coffea histograms to root histograms by uproot3 for 1-dimensional histograms only.

I'm using in my analysis lots of 2-dimensional histograms, so i wrote conversions

• counter (processor.defaultdict_accumulator) -> ROOT.TH1D
• Hist (1D) -> ROOT.TH1D
• Hist (2D) -> ROOT.TH2D

The right place for these is in hist. I have working code which i could supply as a PR once i get a go-ahead.
Cheers,
Sami Lehti (sami.lehti@cern.ch)

[henryiii]

That would be great, a starter PR would be appreciated :)

[slehti]

A new file in hist/src/hist?