NAME
    gtbindef Generate an energy or time bin definition (FITS) file 
    to be used with gtbin.


USAGE
    gtbindef bintype binfile outfile energyunits


DESCRIPTION

gtbindef creates the input (FITS) file needed by the gtbin tool (see
the gtbin help) in order to generate customized binning in energy or
time of Fermi event data. This tool complements the gtbin tool and
is used in combination with it. A user may, for example, wish to create
a light curve with non-uniform binning, in the case of flaring or
transient sources.
  

PARAMETERS

bintype [string: E|T]
Type of bins the user wants to generate; energy bins (E) or time 
bins (T). 

binfile [file]
File containing the ASCII bin definitions. This file must be created
by the user. The range (minimum and maximum values) of each bin may be
specified, one per line. The code considers the numbers in this file
to be floating point. See the example below.
      
Outfile [file]
Name of the output FITS file containing the bin definitions. This file
will be an input to gtbin (see the gtbin help).
  
energyunits = MeV [string: eV|keV|MeV|GeV] 
Units of input energy bins: GeV, MeV, keV, or eV.
Note that the time units are always in seconds. For Fermi data files
this should be in MET. 
	 	 
(chatter)  
This parameter fixes the output verbosity: no screen output (0),
nominal screen output (2), maximum verbosity (4). The default value is
2.

(clobber = yes)        
Overwrite or do not overwrite existing output files. The default value is: "yes".

(debug = no)   
Activate debugging mode. The default value is "no". When debug is
"no", all exceptions that are not caught and handled by individual
tool-specific code are caught by a top-level exception handler that
displays information about the exception and then exits. When debug is
"yes", such exceptions are not caught by the top level code. Instead
the tool produces a segmentation violation, which is more useful for
debugging. When debugging mode is enabled, the tool produces more
verbose output describing any errors or exceptions that are
encountered.

(gui = no) 
Graphical user Interface (GUI) mode activated if "yes" is
specified. The default value is "no".

(mode = ql)
Mode of automatic parameters. The default value is "ql". 

        
EXAMPLES

The way that the parameters are passed follows the FTOOLs model: They
can be passed interactively by answering a prompt, as a list in a
command line, or by editing the parameter file.

To be prompted for gtbindef simply type in the command line: 

>gtbindef

This will prompt for parameter values. Beware that not all parameters
are prompted: some of the parameter are "hidden".  in order to change
one of the "hidden" parameter, specify its value in the command
line. For example to prevent overwriting an existing output file, type
in the command line:
 
>gtbindef clobber=no  
 

An example of how to use gtbindef to create a FITS 
file to be used subsequently by gtbin to generate 
specific energy binning is given below.

The first step is to create the ASCII file that is input in
gtbindef. That ASCII file should have the initial and final energies
for each bin. For example, suppose the input ASCII file is named
energy_bins_gtbindef, and it contains:
30  50
50 100
100 300
300 1000
1000 3000
3000 10000
10000 200000

(The code considers these numbers as reals).

Then gtbindef could be run as follows:

> gtbindef
This is gtbindef version ScienceTools-v9r33p0-fssc-20140317
Type of bins, E -- energy or T -- time [E] : 
File containing the ascii bin definitions [] : energy_bins_gtbindef
Output file name [] : energy_bins_gtbindef.fits
Units of input energy bins: MeV, GeV, keV, or eV [MeV] : 

In this case an energy binning was selected (bintype = E). The name of
the ASCII file is "energy_bins_gtbindef", and it is passed in the
binfile parameter (binfile = energy_bins_gtbindef). The output FITS
file is energy_bins_gtbindef.fits (outfile =
energy_bins_gtbindef.fits), and the units used are MeV (energyunits =
MeV).

After running gtbindef, run gtbin to create the spectra using the
selected bins. See the gtbin documentation for more information.


KNOWN BUGS


SEE ALSO

    * gtbin 
    

   

