FBSUB (Mar97)                  ftools.xte                  FBSUB (Mar97)



NAME
    fbsub -- Subtracts a baseline (unpulsed  contribution)  from  an  fB
    histogram.
    
    
USAGE
    fbsub infile outfile phasemin phasemax clobber
    
    
DESCRIPTION
    fbsub  allows  the  user to specify one or two phase ranges that are
    considered to be  free  of  pulsed  signal,  and  to  use  these  to
    determine  the  background,  or baseline (unpulsed), spectrum.  This
    spectrum is then subtracted from the counts stored in  the  fB  file
    to   yield   a  background-  subtracted  pulsed  lightcurve/spectrum 
    two-dimensional histogram.
    
    Input is an fB file; output is an fB file, too.  It does not hurt to
    apply fbsub multiple times, though it does not do much good, either:
    the result is the same as when the  last  fbsub  run  was  performed
    directly  on  the  original  input  fB  file.  Errors are propagated
    rigourously.
    
    
PARAMETERS
    
    infile [string]
        Name of the input fB file (produced by fasebin).
    
    outfile = fBsub.pha [string]
        Name of the baseline-subtracted fB file.
    
    phasemin = 0.0 [double] 
        With phasemax, sets the range of phases to be used to  determine
        the unpulsed contribution.
    
    phasemax = 1.0 [double] 
        With  phasemin, sets the range of phases to be used to determine
        the unpulsed contribution.   phasemax  should  be  greater  than
        phasemin and may exceed 1.0.
    
    (phasemin2 = -100.0) [double]
        With  phasemax2,  sets  an optional second range of phases to be
        used to determine the  unpulsed  contribution.   Negative  value
        indicates that no second range is to be used.
    
    (phasemax2 = -100.0) [double] 
        With  phasemin2,  sets  an optional second range of phases to be
        used to determine the unpulsed contribution.   phasemax2  should
        be greater than phasemin2 and may exceed 1.0.
    
    (clobber = yes) [boolean]
        Should a pre-existing output file be overwritten?
    
    (mode = ql) [string]
        FTOOLS internal -- users should not need to change.
    
    
EXAMPLES
    
    
NOTES:
    See the help file for FASEBIN for details.
    
    
BUGS
    
    Please report problems to xtehelp@athena.gsfc.nasa.gov.
    
    
SEE ALSO
    FASEBIN FBADD FBFSUM FBSSUM