CONVERT
Keywords: greg

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CONVERT

            [GREG2\]CONVERT  A0  D0  [Angle] [/TYPE Ptype] [/UNIT Unit] [/SYSTEM
        EQU|GAL [Equinox]] [/VARIABLE Var_X Var_Y]

        The command converts coordinates in a given  projection  and  coordinate
        system to GREG current ones:

          * Input:
            - Coordinates  are  found in Var_X and Var_Y if the option /VARIABLE
              is present, else buffers X and Y are used. Var_X and Var_Y must be
              DOUBLE  precision,  writeable, 1-dimensional arrays. If input pro-
              jection type is NONE, values are absolute  spherical  coordinates.
              Else they are offsets from the projection center.
            - The  unit of coordinates can be set with the option /UNIT with the
              argument SECOND, MINUTE, DEGREE, or  RADIAN.  Default  is  current
              Greg angle unit (see HELP G\SET ANGLE_UNIT).
            - Input  coordinate  system  is  set with the option /SYSTEM EQU|GAL
              [Equinox]. Default equinox is 2000 if system is Equatorial.
            - Input projection is  defined  by  CONVERT  A0  D0  [Angle]  [/TYPE
              Ptype].  A0  and  D0  are the coordinates of the projection center
              (reference of the offset coordinates). They  are  relevant  except
              for  the NONE projection. Format is degrees in sexagesimal strings
              (A0 is hour angle if input system is EQUATORIAL). Angle, if  rele-
              vant,  must  be  set in degrees. Supported types can be found with
              CONVERT /TYPE ?. Default is NONE.

          * Output:
            - Converted coordinates are saved in the input variables  (overwrit-
              ten).  If the current Greg projection is NONE, values are absolute
              spherical coordinates. Else they are offsets from the current Greg
              projection center.
            - The  unit  of output coordinates is always natural units (i.e. the
              equivalent of Radians after reprojection).
            - Output coordinate system is the current Greg one (see SHOW  SYSTEM
              and HELP SET SYSTEM).
            - Output  projection  (center and type) is the current Greg one (see
              HELP PROJECTION).

        There is no provision for "hidden" parts which are  treated  exactly  as
        visible ones.

Subsections

- CONVERT EXAMPLES