next up previous contents index
Next: LIMITS /BLANKING Up: GREG1 Language Internal Help Previous: LABEL /Y   Contents   Index


LIMITS

        [GREG1\]LIMITS  [X1  X2  Y1  Y2  [Unit]]  [/XLOG]  [/YLOG] [/RGDATA]
    [/BLANKING Bval Eval] [/REVERSE [X] [Y]]  [/VARIABLES  Array_X  Array_Y]
    [/MARGIN [...]]

    Sets the coordinates of the plot region. The limits are the user coordi-
    nates of the BOX corners, and  in  conjunction  with  the  BOX_LOCATION,
    specifies the conversion formula between USER and PLOT coordinates.

    The limits can be computed from different data:
      - if  LIMITS  has no arguments, it will compute automatic limits using
        data from the most recent COLUMN X and Y, if any,
      - if the option /RGDATA is present, the current Regular  Grid  map  is
        used, if any,
      - if  the  option /VARIABLES Array_X Array_Y is present, the named SIC
        variables are used.
    Options /RGDATA and /VARIABLES are exclusive.

    Some special characters are allowed instead of numerical values for  the
    limits :
          *   Compute automatic limit for this argument
          <   Compute automatic limit for this argument, and take
              the minimum of this value and the precedent limit.
          >   Same as above, but take the maximum.
          =   Keep the precedent value for this limit.

    An  additional  argument  can be used when a projection and a system are
    defined. It may take values
      - RADIAN : The values are assumed to be normal  projected  coordinates
        from the projection center.
      - SECOND,  MINUTE or DEGREE : The values are converted from the speci-
        fied angular unit to radians. They still represent offsets from  the
        projection center.
      - ABSOLUTE  : The values are assumed to be absolute coordinates on the
        sphere. APPROXIMATE corresponding projected coordinates are computed
        from these values (the projected coordinates are necessarily approx-
        imate since in general e.g. the upper left and lower left corner  of
        the box correspond to different absolute Right ascension for Equato-
        rial system).
    The default value is the current angle unit as defined by SET ANGLE.


Subsections

Gildas manager 2024-03-29