my_star/StRoot/StFlowAnalysisMaker/README

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Maker:		StFlowAnalysisMaker
Files:		StFlowAnalysisMaker.cxx
		StFlowAnalysisMaker.h
		StFlowCumulantMaker.cxx
		StFlowCumulantMaker.h
		plot.C
		plotCen.C
		plotMinBias.C
		plotCumulant.C
		minBias.C	
Authors:	Art Poskanzer and Raimond Snellings
		with lots of help from Glenn Cooper 
Date:		Dec 1999
Description:

Makes histograms for the flow analysis. It reads the event and
particle quantities from StFlowEvent. It removes autocorrelations of
each particle with respect to the event plane and for each harmonic
makes a 2D histogram of the number flow, v, vs. y and p_t.

In Finish, it calculates the event plane resolution from the
correlation of sub-event event planes. It then corrects the v
histograms for the event plane resolution. For the doubly-integrated v
values the error on the event plane resolution is folded in to the
error. It calculates the PhiWgts needed to make the event plane
isotropic in the lab and outputs them as flowPhiWgtNew.hist.root . To
use these PhiWgts in the next analysis you have to copy this root file
to flowPhiWgt.hist.root . If the file flowPhiWgt.hist.root is missing
the PhiWgts are set to 1.0 .

The CumulantMaker performs the new and old cumulant analysis.

The AnalysisMaker outputs to flow.hist.root and the CumulantMaker to
flow.cumulant.root .

The macro doFlowEvents.C in StRoot/macros/analysis runs these
programs. Many of the parameters, flags, cuts, and selections can be
set from this macro without recompiling the code. If you instantiate
the CumulantMaker you must first instantiate the AnalysisMaker.

The macro plot.C is for plotting the histograms and their
projections. It reads flow.hist.root or an anaXX.root file. It asks
for a run number which will be printed at the bottom left of the
plot. It presents you with a menu of possible plots. If you know the
plot number you want you can invoke the macro with that number as an
argument. If you execute the macro with all three arguments (plot
number, selection number, harmonics number) for a graph that has
multiple harmonics and selections, it will plot only the histogram for
that selection and harmonic. After it has been loaded and executed
once, it can be rerun simply with plot().

The macro plotCumulant.C does the same for the cumulant histograms by
reading flow.cumulant.root or an anaXX.root file.

The macro plotCen.C reads a set of histogram files for different
centralities and plots one histogram from each file on the same
page. The interface is similar to plot.C.

The macro plotMinBias.C reads a set of histogram files for different
centralities and combines the histograms them with yield weights so
as to obtain a minimum bias histogram. The interface is similar to
plot.C.

The macro minBias.C reads a set of histogram files for different
centralities and outputs another root file with the yield weighted
combination of the histograms.