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Abstract
I/O
Examples
Particulars
Required Reading
Version
Index_Entries

Abstract


   CSPICE_SURFNM computes the double precision, outward-pointing
   normal unit 3-vector at a point defined on the surface of an 
   ellipsoid. 

   For important details concerning this module's function, please refer to
   the CSPICE routine surfnm_c.

I/O

   
   Given:
   
      a,       the scalar double precision values of the ellipsoid's 
      b,       triaxial radii ellipsoid, where:
      c
                  'a' is length in kilometers of the semi-axis of the ellipsoid
                   parallel to the x-axis of the body-fixed reference frame 
   
                  'b' is length in kilometers of the semi-axis of the ellipsoid
                   parallel to the y-axis of the body-fixed reference frame 
   
                  'c' is length in kilometers of the semi-axis of the ellipsoid
                   parallel to the z-axis of the body-fixed reference frame 
   
      point   a double precision 3-vector defining a location on
              the ellipsoid
   
   the call:
   
      cspice_surfnm, a, b, c, point, normal
   
   returns:
   
      normal   a double precision unit 3-vector normal to the 
               ellipsoid at 'point' in the direction away from the
               ellipsoid
   

Examples


   Any numerical results shown for this example may differ between
   platforms as the results depend on the SPICE kernels used as input
   and the machine specific arithmetic implementation.

   
      ;;
      ;; Define the radii of an ellipsoid. 
      ;;
      a  =  1.d
      b  =  2.d
      c  =  3.d
   
      ;; 
      ;; Select a location.
      ;;
      point = [ 0.d, 0.d, 3.d ]
   
      ;;
      ;; calculate the surface normal to the ellipsoid at 'point'.
      ;;
      cspice_surfnm, a, b, c, point, out_norm
      print, out_norm
   
   IDL outputs:
   
        0.0000000    0.0000000    1.0000000
   

Particulars


   None.

Required Reading


   ICY.REQ
   ELLIPSES.REQ

Version


   -Icy Version 1.0.0, 16-JUN-2003, EDW (JPL)

Index_Entries

 
   surface normal vector on an ellipsoid 
 



Wed Apr  5 17:58:04 2017