
ctulimit
========

Computes upper flux limit for a source model.


Synopsis
--------

This tool computes the upper flux limit for a specific source model. Except
of the node function, all spectral models are supported. Starting from the
maximum likelihood model parameters, the tool finds the model flux that leads
to a decrease of the likelihood that corresponds to a given confidence level.
By default a confidence level of 95% is used, but this level can be adjusted
using the hidden confidence parameter.

ctulimit writes the differential upper flux limit at a given reference 
energy (specified by the hidden parameter eref) and the integrated 
upper flux limit (specified by the hidden parameters emin and emax)
into the log file.



General parameters
------------------

inobs [file]
    Input event list, counts cube or observation definition XML file.
 	 	 
inmodel [file]
    Input model XML file.
 	 	 
srcname [string]
    Name of source model for which the upper flux limit should be computed.
 	 	 
expcube [file]
    Input exposure cube file (only needed for stacked analysis).

psfcube [file]
    Input PSF cube file (only needed for stacked analysis).

bkgcube [file]
    Input background cube file (only needed for stacked analysis).

caldb [string]
    Calibration database.
 	 	 
irf [string]
    Instrumental response function.
 	 	 
(edisp = no) [boolean]
    Applies energy dispersion to response computation.
 	 	 
(confidence = 0.95) [real]
    Confidence level of upper limit.
    
(sigma_min = 0.0) [real]
    Minimum boundary to start searching for upper limit value.
    Number of standard deviations above best fit value
    
(sigma_max = 10.0) [real]
    Maximum boundary to start searching for upper limit value.
    Number of standard deviations above best fit value  
 	 	 
(eref = 1.0) [real])
    Reference energy for differential limit (in TeV).
 	 	 
(emin = 1.0) [real])
    Minimum energy for integral flux limit (in TeV).
 	 	 
(emax = 100) [real]
    Maximum energy for integral flux limit (in TeV).
 	 	 
(tol = 1e-5) [real]
    Computation tolerance.
   
(max_iter = 50) [integer]
    Maximum number of iterations before stopping the upper
    limit computations.


Standard parameters
-------------------

(chatter = 2) [integer]
    Verbosity of the executable:
     chatter = 0: no information will be logged
     
     chatter = 1: only errors will be logged
     
     chatter = 2: errors and actions will be logged
     
     chatter = 3: report about the task execution
     
     chatter = 4: detailed report about the task execution
 	 	 
(clobber = yes) [boolean]
    Specifies whether an existing output file should be overwritten.
 	 	 
(debug = no) [boolean]
    Enables debug mode. In debug mode the executable will dump any log file output to the console.
 	 	 
(mode = ql) [string]
    Mode of automatic parameters (default is "ql", i.e. "query and learn").

(logfile = ctulimit.log) [string]
    Name of log file.


Related tools
-------------

ctlike
cterror
ctbutterfly
