View source for Performing Dithering Corrections

This code uses data taken during beam modulation, or dithering. It uses 5 bpms ''diff_4aX, diff_4aY, diff_4eX, diff_4eY'', and ''diff_12X'' as independent variables (IVs), and the 4 main detectors ''asym_usl, asym_usr, asym_dsl'', and ''asym_dsr'' as dependent variables (DVs). It calculates the dithering slopes and uses either the slopes from a single run or the average slopes over a slug to correct the DVs.

== Getting Started ==
First, you will need to find the slopes that you will use to perform the correction.
# Login to the apar account on aonl2: <code>ssh apar@aonl2 </code>
# <code> cd ~/PREX/prompt/beam-mod/rootfiles </code>
# <code> source setup_japan.tcsh </code>
# Choose a list of runs that you would like to analyze and put them in a file called "filename.list"
#* To analyze a slug, choose the list in <code> ~/PREX/prompt/collector/run_list/ </code>
# Next, run <code> ./dit_runlist.sh filename.list </code>

This creates a root file called "dit_slopes_filename.root" in the <code> cd ~/PREX/prompt/beam-mod/rootfiles </code> directory.

It contains the following variables:
#run: The runnumber
#''DV''_''IV'': the slope of the graph of ''DV'' vs IV''
#* '''Example:''' usr_4aY contains the slopes of asym_usr vs diff_bpm4aY
#* There is one for each pair of the following variables:
#** DV: asym_usl, asym_usr, asym_dsl, asym_dsr
#** IV: diff_bpm4aX, diff_bpm4aY, diff_bpm4eX, diff_bpm4eY, diff_bpm12X

<span style="color:red"> Describe how to create a root file that has all the slopes here </span>

== Setting up for analysis ==
To get set up, all you have to do is make sure you know the run number you would like to correct. 
=== QuerySlugNumber.C ===
Give this macro your run number, and it will tell you what slug it belongs too

=== black.list ===
This file is a list of all the runs whose slopes are "outliers" and should not be used. To check that your slopes are good:


== Running the analysis ==
There are two scripts that have several options that you can control.

=== DitAlias.C ===
This macro will use slopes from either a specific run number or the average from a slug, and uses them to correct the detector asymmetries. It draws plots of the detector asymmetry before and after the correction.

=== CorrectTree.C ===
This macro will use the slug average to correct the detector asymmetries. It saves the uncorrected and corrected detector asymmetries to a root file.