Documentation Request: ROOT IO of JAPAN outputs and EPICs data in PANGUIN

[cameronc137]

Is your feature request related to a problem? Please describe.
There are many ways to read and write root trees (from JAPAN or otherwise), as well as EPICs data (reading and writing - for stripcharts and alarm handling), and if we could keep all of that information together and in a concise set of examples that would be really helpful.

Describe the solution you'd like
A wiki section in here and also a set of example macros/.cfg files with ROOT IO (reading and writing new root trees I guess) and EPICS calls

Describe alternatives you've considered
Just sticking with data handler manipulation for new data and just using tree Draw() commands forever

Additional context
I like to document everything

[cameronc137]

If we could replicate the CMake procedure for including JAPAN .so files for doing root analyses that was developed for remoll recently that would be great as well.

See JeffersonLab/remoll#159

[cameronc137]

We got an example JAPAN macro that does complex ROOT IO to work in https://github.com/JeffersonLab/japan/tree/feature-panguin-macros

[cameronc137]

A few examples of ROOT IO that work as exemplified in aggregator code:

Get a leaf from a chain:

japan/rootScripts/aggregator/camIO.hh

Line 214 in a50ef86

TLeaf * Leaf = Chain->GetLeaf(branch);

Assign a branch address from a known branch name:

japan/rootScripts/aggregator/camIO.hh

Line 318 in a50ef86

oldTree->SetBranchAddress(branchList[k],&oldValues[k]); // Set old branch addresses

Using a TTreeReader to do the same but more intelligently:

japan/rootScripts/aggregator/regressor/camReg.hh

Line 104 in a50ef86

TTreeReaderValue<Double_t> temp1(oldTreeReader,oldManipulatedDataBranchList[iBranch]);