A header only library built on top of ROOT to perform operations on collections, fast and easily
sqrt(v0*v0 + v1*v1) / 3
TVec solves two probelms:
- Allow to naturally express operations on collections of values which are common in analysis
- Act as a view on other collections with a contiguous memory region associated. An example are TTreeReaderArray's. This indeed allows to solve problem 1) in the context of TDataFrame based analysis.
TVec<T> and the related operators are implemented exploiting advanced template metaprogramming: it strives to achieve generality and performance at the same time.
The main class of the library is TVec<T>, which has the following nice properties:
- has a storage associated which is contiguous (yes, almost all operations rely on autovectorisation)
- offers the same interface of
std::vector<T> - supports +, -, *, /, <, <=, ==, >=, >, != operators in combination other TVecs and with scalars (for example numbers)
- supports trivial math functions such as the trigonometrical ones, exp, log and sqrt
- plays well with helper functions such as Dot, Sum, Filter
- it is written on ROOT files as a
std::vector<T>
Please have a look into the test directory!
E. Guiraud, D. Piparo, E. Tejedor 2018 Copyright CERN