Documentation of libsbsdig » History » Revision 53
Revision 52 (Eric Fuchey, 08/18/2020 11:37 PM) → Revision 53/120 (Eric Fuchey, 08/18/2020 11:44 PM)
h1. Documentation of libsbsdig This page concerns the new version of libsbsdig which is currently being developped. The documentation for the old version of libsbsdig has been saved at: https://redmine.jlab.org/projects/sbs-software/wiki/Old_Doc_libsbsdig h2. Overview This page is maintained by the UConn group (Eric Fuchey + Andrew Puckett) and as of February 14, 2020 is specific to the *sbsdig_lw* branch of libsbsdig on github. h2. Purpose This page documents the libsbsdig code, which purpose is to process the Monte Carlo simulations of the SBS experiments produced by G4SBS [https://hallaweb.jlab.org/wiki/index.php/Documentation_of_g4sbs] to produce ADCs or TDCs. It is a standalone program which can run with a limited number of outputs (see section on usage). These produce files which can be analyzed with SBS-offline [https://hallaweb.jlab.org/wiki/index.php/Documentation_of_SBS-offline]. h2. Getting the code and building the program h3. Prerequisites *Working [https://root.cern.ch/drupal/ ROOT] installation. '''libsbsdig is compatible with ROOT [https://root.cern.ch/drupal/] installation. *ROOT version 5 and ROOT version 6'''. '''''ROOT 6 is strongly recommended*. recommended''''' *Working G4SBS [https://hallaweb.jlab.org/wiki/index.php/Documentation_of_g4sbs] [https://hallaweb.jlab.org/wiki/index.php/Documentation_of_g4sbs G4SBS] installation. h3. Downloading the repository The code is hosted on a github repository owned by JLab. To clone via ssh (preferred method on JLab batch farm), do: bq. git clone git@github.com:JeffersonLab/libsbsdig.git For this method to work, the ssh public key on the machine where you want to get the code must be added to your github account (see [https://help.github.com/articles/generating-ssh-keys/ Guide] to generating ssh keys and adding to your github.com account.) Cloning the repository defaults to the "master" branch. _As of August, 18th, 2020, the master branch still contains the old version of the code_. To obtain the new version of the code currently being developped on the "sbsdig_lw" branch, do bq. git checkout sbsdig_lw h3. Building and installing the library Create a "build" directory that is parallel to the "libsbsdig" source directory (this is not strictly required, but the build directory must be separate from the "SBS-offline" directory in any case). You also need to have setup an installation path e.g. /path/to/libsbsdig-install *NB*: similarly to the build directory, the /path/to/libsbsdig-install directory shall '''not''' be the same as the source directory! _The following instructions assume that "build" is parallel to "libsbsdig":_ If successful, the libsbsdig library and several other files and folders will be created in the "build" and the "install" directory. To build and install, the procedure needs to be completed. From scratch: bq. mkdir build cd build cmake -DCMAKE_INSTALL_PREFIX=/path/to/libsbsdig-install ../libsbsdig make install Then, the following line should be added in the OS login configuration file to take advantage of this functionality: * source /path/to/libsbsdig-install/bin/sbsdigenv.sh (or source /path/to/g4sbs_install/bin/sbsdigenv.csh on the batch farm) h2. How to use the digitization library When sbsdig is installed in your machine, you can run the program using up to 4 arguments: bq. sbsdig gmn13.5_elastic_prod.txt 100000 gmn13.5_beambkgd_prod.txt 15 These arguments have to come in this sequence, and while not all arguments are mandatory to provide, one cannot skip an argument unless they want to skip all following arguments. *The first argument is a list of "signal" files to digitize. It is mandatory to provide. An example is provided in the files attached. *The second argument is the number of process. It has a default value of "-1" (=2^64-1) so it can be left unprovided, unless one wants to provide argument 3 and 4. *The third argument is a list of "background" files (usually min-bias beam-on-target) to superimpose to the signal to digitize. It can be ignored if one seeks to digitize signal with no background. An example is provided in the files attached. *The fourth argument is the number of "background" files to superimposeto the signal to digitize. It's default value is zero, so it can be ignored if one seeks to digitize signal with no background. h2. Root output documentation The new digitization library will expand the TTree object from the input file to add ADC and TDC values. The input tree structure from G4SBS has already been described in detail [https://hallaweb.jlab.org/wiki/index.php/Documentation_of_g4sbs#ROOT_Tree_Structure here].