You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
139 lines
6.4 KiB
139 lines
6.4 KiB
\midheading{Output}
|
|
\label{sec:output}
|
|
|
|
In addition to the direct output of the program to {\tt stdout}, after
|
|
all integration regions have completed the warmup stage and a subsequent
|
|
sweep has been made for each contribution, the program will
|
|
produce additional output files as specified below.
|
|
If a working directory was specified in the command line, then these
|
|
output files will be written to that directory.
|
|
|
|
The standard output will detail the iteration-by-iteration best estimate
|
|
of each contribution to the total cross-section, together with the
|
|
accompanying error estimate. Estimates of the total cross-sectio, summing
|
|
over all contributions, will be reported in the form:
|
|
\begin{verbatim}
|
|
Value of integral is 11.7521 0.58456E-02 nb
|
|
\end{verbatim}
|
|
|
|
Other output files may be produced containing various histograms associated
|
|
with the calculated process. The write-out of the different output files
|
|
is controlled by the logical variable {\tt nohistograms} in the {\tt extra}
|
|
section. The default value of this variable is {\tt .false.}, but setting it
|
|
to {\.true.} may be useful for faster running if no histograms are required.
|
|
|
|
Histograms are written to a srries of files with the generic naming structure:
|
|
\begin{verbatim}
|
|
procname_part_lhapdfset_scale_facscale_runstring_histoname.txt
|
|
\end{verbatim}
|
|
where {\tt procname} is a label assigned by the program corresponding to
|
|
the calculated process; {\tt histoname} is the name of the histogram specified
|
|
in the plotting routine (see below) and the remaining labels are as input
|
|
by the user in the file {\tt input.ini}.
|
|
|
|
A default set of histograms is filled for each process. A snippet of
|
|
the histogram output is repeated below:
|
|
\begin{verbatim}
|
|
# W rapidity
|
|
# underflow 0.0000000 0.0000000
|
|
# overflow 0.0000000 0.0000000
|
|
# sum 10453523. 7919.1419
|
|
# xmin xmax cross numerror
|
|
-6.0000000 -5.8000000 0.0000000 0.0000000
|
|
-5.8000000 -5.6000000 0.0000000 0.0000000
|
|
-5.6000000 -5.4000000 0.0000000 0.0000000
|
|
-5.4000000 -5.2000000 0.0000000 0.0000000
|
|
-5.2000000 -5.0000000 7.1413485 0.24680943
|
|
-5.0000000 -4.8000000 1289.2697 28.436126
|
|
-4.8000000 -4.6000000 11218.037 211.10230
|
|
-4.6000000 -4.4000000 36844.231 656.21780
|
|
\end{verbatim}
|
|
The header lines provide the name of the histogram and the accumulated
|
|
cross-section and uncertainty entering the bins ({\tt sum}),
|
|
as well as any underflow or overlow outide the bins (zero in this case).
|
|
The following lines report the results in each bin, in the format:
|
|
bin lower edge, bin upper edge, accumulated cross section, uncertainty.
|
|
The units of the reported cross-section is femtobarns.
|
|
|
|
To modify existing, or add new, histograms one must edit the plotting
|
|
routine specified in each process description. These are found in
|
|
the directory {\tt src/User/} and correspond to the (default) value
|
|
{\tt .false.} for the flag {\tt newstyle} in the {\tt histogram} section.
|
|
|
|
Additional plotting infrastructure was include in the release
|
|
of CuTe-MCFM, which is enabled by setting {\tt histogram\%newstyle = .true.}
|
|
in the input file.
|
|
At present this is only possible for the processes
|
|
$W^\pm$, $Z$, $H$, $\gamma\gamma$, $Z\gamma$, $ZH$,
|
|
$W^\pm H$, $WW$, $W^\pm Z$ and $ZZ$.
|
|
It is the default for the CuTe-MCFM example input files.
|
|
The predefined plotting routines that can be adjusted in this case are,
|
|
for example for $Z$ production, in the file
|
|
{\tt src/User/nplotter\_Z\_new.f90}, and similarly for the other processes.
|
|
|
|
A brief description of the two alteratives for the plotting routines is
|
|
provided in the subsections below.
|
|
|
|
\bottomheading{Traditional histograms ({\tt newstyle = .false.})}
|
|
\label{sec:oldhistos}
|
|
|
|
Extra histograms may be added to the plotting files in
|
|
a fairly straightforward manner. Each histogram is filled by making
|
|
a call to the routine {\tt bookplot} and updating the histogram
|
|
counter {\tt n} by 1. For example, the rapidity of particle $3$
|
|
may be plotted using the following code fragment:
|
|
|
|
\begin{verbatim}
|
|
eta3=etarap(3,p)
|
|
call bookplot(n,tag,'eta3',eta3,wt,wt2,-4d0,4d0,0.1d0,'lin')
|
|
n=n+1
|
|
\end{verbatim}
|
|
The first two arguments of the call should not be changed. The third
|
|
argument is a string which is used as the title of the plot in the
|
|
output files. The fourth argument carries the variable to
|
|
be plotted, which has been previously calculated. The arguments {\tt
|
|
wt} and {\tt wt2} contain information about the phase-space weight and
|
|
should not be changed. The
|
|
last arguments tell the histogramming routine to use bins of size {\tt
|
|
0.1} which run from {\tt -4} to {\tt 4}, and use a linear scale for
|
|
the plot. A logarithmic scale may be used by changing the final
|
|
argument to {\tt 'log'}.
|
|
|
|
\bottomheading{New histograms ({\tt newstyle = .true.})}
|
|
\label{sec:newhistos}
|
|
|
|
The routine {\tt setup} first allocates the required space to store
|
|
all histograms. For instance, space for 2 histograms is requested with:
|
|
\begin{verbatim}
|
|
allocate(histos(2))
|
|
\end{verbatim}
|
|
Following this, the histograms can be defined either with uniform binning
|
|
or custum bin sizes. For example, the line:
|
|
\begin{verbatim}
|
|
histos(1) = plot_setup_uniform(0._dp,500._dp,10._dp,'mZZ')
|
|
\end{verbatim}
|
|
initializes the first histogram with bins from 0 to 500, of width 10, named
|
|
{\tt mZZ}. The second histogram could be initialized with:
|
|
\begin{verbatim}
|
|
histos(2) = plot_setup_custom([0d0,25d0,50d0,75d0,100d0,150d0,200d0],'ptZZ')
|
|
\end{verbatim}
|
|
This time the first argument sets up the array of bin edges -- 7 edges
|
|
to define 6 bins -- and the histogram is named {\tt ptZZ}.
|
|
|
|
After setup, the routine {\tt book} is called for each phase space
|
|
point. The plotting routine is provided the momentum configuration ({\tt p})
|
|
and associated Vegas weight ({\tt wt}). Given these, it returns the array of
|
|
histograms ({\tt ids}), calculated observables in the
|
|
{\tt vals} array, and Vegas weights in {\tt wts}.
|
|
For instance, for the example above this could be accomplished by:
|
|
\begin{verbatim}
|
|
ptZZ = ptfour(3,4,5,6,p)
|
|
mZZ = puremass(p(3,:)+p(4,:)+p(5,:)+p(6,:))
|
|
ids = histos
|
|
vals = [ptZZ, mZZ]
|
|
wts = [wt, wt]
|
|
\end{verbatim}
|
|
The specification of weights for individual histograms allows the
|
|
the original Vegas weights to be reweighted for particular distributions,
|
|
for instance with the output of the transition function in the case of
|
|
resummed calculations.
|