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ACCUMULATE /NEW

        LAS\ACCUMULATE /NEW [/RESAMPLE [NX Xref Xval Xinc Unit]]

    ACCUMULATE is used to add a pair of spectra together. The T spectrum  is
    added  to  the  R spectrum using the current weighting function (see SET
    WEIGHT). On return R contains the sum spectrum, and  T  the  observation
    previously  in  R. To add more than 2 spectra, you should build an index
    and AVERAGE it in a single step instead (this  will  prevent  cumulative
    resamplings,  respect  the  respective weights, and preserve at best the
    noise properties).

    The spectra are added channel by channel by default, if  possible.  Else
    the option /RESAMPLE must be invoked (see subtopic for details).

    As  commands AVERAGE or STITCH, ACCUMULATE checks for the positional co-
    incidence and calibration homogeneity according to  SET  MATCH  and  SET
    CALIBRATION respectively.

    For  EQUAL  weights, ACCUMULATE computes the sum of the two spectra, al-
    lowing addition of an ensemble of spectra after division  by  the  total
    number of spectra. For other weightings, ACCUMULATE computes the average
    of the two spectra.

    ACCUMULATE also works on Continuum drift. The alignement may be  Channel
    or Position in this case.


Gildas manager 2011-04-01