UV_FILTER

        [CLEAN\]UV_FILTER [/RESET] [/ZERO] [/CHANNELS Channel_List]
      [/FREQUENCY List Of Frequencies] [/RANGE Min Max [TYPE]]
      [/VELOCITY List of Velocities] [/WIDTH Width [TYPE]]
      [/FILE FileIn [FileOut]]

    "Filter" line emission, by flagging the corresponding channels. The channels
    can  be  specified either by the /FREQUENCY or /VELOCITY options in combina-
    tion with the /WIDTH option, or by a channel list with /CHANNELS or a  range
    (of channels, frequencies or velocities) with /RANGE.

    By default, channels to be filtered are flagged (weights becoming negative).
    Option  /ZERO can be used to erase them: weights and visibilities are set to
    zero, see HELP UV_FILTER /ZERO. On the contrary, option /RESET can  be  used
    to unflag them (and is thus conflicting with option /ZERO).

    The  command works on the current UV data, unless the option /FILE is speci-
    fied.

    With no options (except possibly /FILE and /ZERO), the  command  behaves  as
    UV_FILTER /CHANNELS PreviewChannels. See UV_PREVIEW for details.