XRONOS (May2002)              xanadu.xronos             XRONOS (May2002)



NAME
    xronos  -- a multi-mission X-ray timing analysis software package.
    
    
USAGE
    xronos
    
    
DESCRIPTION
    Xronos is a general purpose timing  analysis  package.  Although  it
    was  designed  mostly  for  X-ray  astronomy,  Xronos  is  basically 
    detector and wavelength-independent.   Xronos  is  a  collection  of
    programs,  each  dedicated  to  one  task, that use a parameter file
    interface. Parameters may be specified as arguments  when  the  tool
    is executed or prompted from within the tool.
    
    The package contains the following programs:
        ascii2flc - [P] creates a Xronos input FITS file from an ASCII file
          autocor - calculates auto correlation for a time series
         crosscor - calculates cross correlation of two time series
        earth2sun - change times to solar system barycenter
            efold - creates epoch folded lightcurve, hardness and color-color plots
         efsearch - finds best chi-squared period by folding over range of periods
        flc2ascii - [P] Dump Xronos input or output in ASCII file readable by QDP
           lcmath - Subtracts or adds two binned lightcurves.
          lcstats - calculates statistical variables a time series
           lcurve - creates lightcurves, hardness and color-color plots  
         listdata - list data file on the screen 
          powspec - creates power spectrum density  
         rbf2fits - Converts the "EXOSAT rate buffer" format in FITS.
         timeskew - calculates time skewness function for a time series
          xronwin - [P] creates a window file suitable for Xronos tasks 
    
         [P] Perl script.  You must have Perl installed to use this tool.
    
    The  way  to use the Xronos programs is to execute the tasks (listed
    above) from the command line and answer the  prompts.   The  display
    and  graphic  capabilities  of  the Xronos programs are based on the
    PGPLOT  graphic  package,  which   provides   interactive   scaling, 
    labeling  and  fitting capabilities. Text-based help is available by
    running 'fhelp  taskname'.  Input  and  output  files  are  in  FITS
    format.   Complete  documentation  and  examples  are  available  at 
    http://xronos.gsfc.nasa.gov
    
    
    
EXAMPLES
    Examples of how to run each are provided within the  help  for  each
    task  or  on  the web address. To invoke the task just type the task
    name on the command line, e.g. to run the program lcurve type
    
    
       > lcurve
    
    and after answer to each of the questions.
    
    
BUGS
    Report  problems   to   xanprob@athena.gsfc.nasa.gov.    Provide   a 
    detailed description of the problem (with a log file if possible).