README.md

C++ access to QADB

This directory contains the C++ source code to access the QA database

first, make sure you have the rapidjson library; it is a submodule of this repository and can be obtained by
```
git clone --recurse-submodules https://github.com/JeffersonLab/clas12-qadb.git
```
be sure the $QADB environment variable points to the clas12-qadb repository
- this can be done with source ../environ.sh
in your analysis code, add the following directories to your project's include path:
- srcC/include
- srcC/rapidjson/include
- you may need to specify these as "absolute paths" (i.e., not relative paths); see examples/Makefile macro DEPS for an example
see the examples/ directory for example QADB usage in analysis loops
- a standard usage of QA cuts is demonstrated in examples/cutCustom.cpp
usage notes:
- include the QADB.h header, then instantiate
  - QADB is in the QA namespace, so you will either need to add using namespace QA or use specifiers, such as QA::QADB *q
- the QADB class provides several methods for accessing the QA info; you only need to provide it a run number and event number
- database lookups are only performed as needed, so it is safe to use any accessor method in a standard analysis event loop
NOTE QADB has been tested with compiled analysis code, but some users encounter problems when interpreting analysis code with ROOT Cling; it is recommended to compile your analysis code