Local File Access
For general information on file access see FileAccessPatterns.
Below are instructions for testing the read pattern for an ATLAS AOD file (should work with other kinds of root based files too)
Download ROOT > 5.26 (if you want TTreePerfStats)
Setup root: export ROOTSYS= path/to/root; export LD_LIBRARY_PATH = $ROOTSYS/lib; export PATH = $PATH/lib
Make a shared library containing the details of ATLAS AOD branches. Run "root" then
root [0] TFile *f = TFile::Open("YourAODFile.root") root [1] f->MakeProject("aod","*","new++"); root [2] .q
Potentially wait a while, then you should have a directory aod with a lot of things in it including aod.so
To run over this YourAODFile.root file use code like that given in
ReadingAODBranches_ExampleCode
To access files via rfio you will also want a link
ln -s $LCG_LOCATION/lib/libdpm.so libshift.so.2.1
You can then plot the outputs in root
root [0] TFile *f = TFile::Open("OuputAODFile.root") root [1] ioperf.Draw()
To reorder the file use the example also given at ReadingAODBranches_ExampleCode