35th ROOT Parallelism, Performance and Programming Model

Thursday 15 Mar 2018, 16:00 → 17:45 Europe/Zurich

4/S-020 (CERN)

Danilo Piparo (CERN)

Present: Xavi, Guilherme, Enric, Danilo, Jim, Stefan, Philippe, Pere

- TBufferMerger (not intended for 6.13)

Dan had a PR, decided to start from it and eliminate the asynch merge thread. Issue with the single threaded case; linked to the behaviour of TTaskGroup with IMT off.

- VecOps

Ready to go to 6.13, integrated and tutorial available.

- TDF (not intended for 6.13)

Slow down in a TDF analysis identified by CMS user due to the multiple deserialisation of collections with TTreeReeaderArray. A workaround has been provided, work ongoing towards a proper fix.

- Numpy (not intended for 6.13)

Pythonisation layer C++, add property for numpy conversion of Tvec, vector, TVector, TMatrix. Works nicely: segfaults with TVector/TMatrix<int> only. And there are tests. All in the PR.

Enrico: proposes histos to the conversion.

Jim: Proposes the conversion of histos not to arrays but to tuples in order to be able to plot them with python tools, bin edges and bin contents being. Numpy histos do not have error on bins.

- Jitted expressions in TDF (not for 6.13)

Support for jitting branch.leaf available. Now need to generalise for a.b.c.d...leaf, will work on that.

 

16:00 → 16:20 Round Table and Discussion

• 6.13 release
• TBufferMerger
• VecOps
• Release notes
• Numpy - PyROOT integration