SPACING

          CHARACTER*16 SPACING[2]

    SPACING indicates the step (and implicitely the contour levels) for contour-
    ing and/or greyscale. SPACING[1] control the values, and SPACING[2] the Unit
    of  these  values. It can be UNITS (default data cube units), NOISE or SIGMA
    (noise level), Jy (which also stands for Jy/Beam) and its sub-units mJy  (or
    milliJy) and microJy, or K and its sub-units mK (or milliK) or microK.

    Jy (and its sub-units) is taken as equivalent to Jy/Beam, and automatic con-
    version between brightness unit (K) and flux unit (Jy/Beam) is made when the
    data cube has a specified angular resolution and frequency.

    SPACING[1] = 0 means an automatic guess of the contours from the Min and Max
    of the data cube.

    The type of spacing is controlled by  variable SPACE_TYPE.