FRAME

##
FRAME

            [ASTRO\]FRAME System [...]

        This command specifies the reference frame to be used for plots.  System
        may  be HORIZONTAL or EQUATORIAL (at equinox defined by TIME command) If
        no other argument is given, plotting is done in rectangular  coordinates
        representing Azimuth-Elevation or Right Ascension-Declination.  If other
        arguments are given, a Stereographic projection is used:
          - FRAME EQUATORIAL Ra Dec Size
            the projection will be centered on Ra and  Dec  (hours  -  degrees);
            Size  in  degrees  specify  the plotting range (e.g. 180 for a whole
            hemisphere = the default).
          - FRAME HORIZONTAL Az El Size
            same thing, but Az and El are in degrees.
          - FRAME HORIZONTAL Center
            will plot a hemisphere in horizontal system,  where  Center  may  be
            ZENITH, NORTH, EAST, SOUTH or WEST.