COMPARE MAPS

        [DISPLAY\]COMPARE [LeftMap RightMap] [Mode]

    Compare  side by side two 2-D datasets. The LeftMap defines the way both are
    displayed (sizes, contour levels, color scale).  If  neither  is  specified,
    just re-display the last ones.

    Mode  is an optional keyword that indicates which data set controls the size
    (unless SIZE is non zero) and data range (unless SCALE is  non  zero).   Al-
    lowed keywords are
    LEFT    Size and data range taken from LeftMap
    RIGHT   Size and data range taken from RightMap
    JOINT   Data range taken as the union of the Left and Right ranges
    EACH    Data range taken for each map.
    For JOINT and EACH, the size is the union of sizes.

    The maps can be planes of data cubes. For example
            COMPARE CLEAN[2] CLEAN[16]
    will display side by side channel 2 and channel 16 of the CLEAN cube.