TICKSPACE

        [GREG1\]TICKSPACE SmallX BigX SmallY BigY

    Sets  tick  intervals (in User coordinates) for BOX or default intervals
    for AXIS. SmallX refers to the interval between small tick marks on  the
    X  axis, BigX refers to the interval between large ticks, etc. If Big is
    0, the axis routine will supply its own Big intervals according  to  the
    label  limits and use your Small value if non zero. To restore fully au-
    tomatic ticking, set Small and Big equal to 0. To suppress small  ticks,
    specify equal values for Small and Big.

    The Small and Big values are meaningless for LOGarithmic axes, which us-
    es their own conventions. If two major ticks are separated:
      - by one decade, the minor ticks are at  all  unitary  values  of  the
        decade,
      - by two decades, the minor ticks are at values 2, 5, 10, 20, and 50,
      - by  three  or more decades, the minor ticks are at (some of) the in-
        termediate decades.

    When using the /ABSOLUTE or /UNIT option for axis-drawing commands,  one
    has to keep in mind that Small and Big (if not 0) should be expressed:
      - in seconds of arc for declination or galactic (sexagesimal notation)
        axis, /ABSOLUTE option (one can usually multiply by 3600 the desired
        tick spacing)
      - in  seconds of time for right ascension axis, /ABSOLUTE option (mul-
        tiply by 12)
      - in seconds, minutes or degrees when option  /UNIT [SECOND|MINUTE|DE-
        GREE] is used.
    Thus in the case of a user-defined tick spacing, TICKSPACE must be rede-
    fined before using another option.