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


        [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.


Gildas manager 2021-09-24