NAME

       NGGSOG - Returns the latitudes and longitudes of six points defining a five-pointed star
       at a given point on the surface of the globe.

SYNOPSIS

       CALL NGGSOG (SLAT,SLON,SRAD,ALAT,ALON)

C-BINDING SYNOPSIS

       #include <ncarg/ncargC.h>

       void c_nggsog(float slat, float slon, float srad, float *alat,
       float *alon)

DESCRIPTION

       SLAT        (an input expression of type REAL) is the latitude, in degrees, of a point on
                   the globe defining the center of the star.

       SLON        (an input expression of type REAL) is the longitude, in degrees, of a point on
                   the globe defining the center of the star.

       SRAD        (an input expression of type REAL) specifies the great-circle distance, in
                   degrees, from the center of the star to the end of one of its points.

       ALAT        (an output array, of type REAL, dimensioned 6) is an array in which the
                   latitudes of points on the star are to be returned.

       ALON        (an output array, of type REAL, dimensioned 6) is an array in which the
                   longitudes of points on the star are to be returned.

C-BINDING DESCRIPTION

       The C binding argument descriptions are the same as the FORTRAN argument descriptions.

USAGE

       Let C represent (CLAT,CLON), let O represent the center of the globe, and let P represent
       the end of one point of the star.  Then, the angle POC has the magnitude specified by
       SRAD.

       SIN, COS, and TAN are used to generate points representing a star having the desired
       radius and centered at the the point with latitude 0 and longitude 0.  These points are
       then subjected to two rotations - one that brings the star up to the desired latitude, and
       another that carries it to the desired longitude.

       NGGSOG is intended to be used for relatively small stars marking points of interest on the
       surface of the globe; using SRAD = 90 degrees is guaranteed to get you into trouble and
       SRAD < 10 degrees is recommended.

EXAMPLES

       Use the ncargex command to see the following relevant example: cpex10.

ACCESS

       To use NGGSOG or c_nggsog, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c,
       preferably in that order.

MESSAGES

       None.

SEE ALSO

       Online: nggcog(3NCARG), ngritd(3NCARG).

COPYRIGHT

       Copyright (C) 1987-2009
       University Corporation for Atmospheric Research
       The use of this Software is governed by a License Agreement.