CLEAN

        CLEAN

    This   task   contains   implementations   of   several   CLEAN-like de-
    convolution  algorithm.  The algorithm is selected through  the  METHOD$
    keyword, which can be :
     SIMPLE    :  The straightforward direct method.
     CLARK     :  The Barry Clark major-minor cycle method.
     MRC       :  a Multi-Resolution Clean.
     THRESHOLD :  Components are not restricted to be point sources.

    The input map and beam should have the same sizes, except  for  the SIM-
    PLE  method where different beam sizes are allowed, and  must  have  the
    same grid spacing.  Sources are searched only in the  inner  quarter  of
    the  map,  but  their  sidelobes are removed in the full map.  A smaller
    search box can be specified if desired.

    The  program can process all planes of a data cube at the same time, but
    a  separate list of component will be  produced  for  each  plane.   The
    cleaning cannot be restarted.