clean

command list , class list , introduction .
 CLEAN N1 N2 N3 THRLO THRHI SET -- Reject outliers from a series of similar
                                   spectra.
 Parameters: 
     
  N1    -- Slot number of first spectrum to correct
  N2    -- Slot number of last spectrum to correct
  N3    -- Slot of first output 
  THRLO -- Lower reject threshold
  THRHI -- Upper reject threshold
  EFAC  -- Factor to multiply errors on rejected points by. e.g. to 
           reduce their weight in subsequent analysis.
  SET   -- Mask regions to be corrected

 The spectra should all be of the same length (checked) and have the 
 roughly the same wavelength scale (not checked). The routine first
 normalises each spectrum by its mean over the required region, and then
 compares each pixel of each spectrum with its equivalent in the other
 spectra. If it is too far out, its values is replaced with the value
 predicted from the others. The error bars of the spectra are used to
 scale the deviations but a separate computation is made to compute the
 scatter at each pixel. The error bars are used to the extent that if
 the scatter is very small by chance, it will not cause rejection of
 good points.

This command belongs to the classes: fudging .


Tom Marsh, trm@astro.soton.ac.uk, Tue Oct 27 08:56:34 1998 .