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Abstract
I/O
Examples
Particulars
Required Reading
Version
Index_Entries

Abstract


   CSPICE_PL2PSV returns a point and two orthogonal spanning vectors that 
   generate a specified plane.

   For important details concerning this module's function, please refer to
   the CSPICE routine pl2psv_c.

I/O


   Given:

      plane   a structure describing a SPICE plane. The structure has
              the fields:

                 normal:   [3-array double]
                 constant: [scalar double]

   the call:

      cspice_pl2psv, plane, point, span1, span2

   returns:

      point    a double precision 3-vector

      span1    a double precision 3-vector

      span2    a double precision 3-vector

               are, respectively, a point and two orthogonal
               spanning vectors that generate the geometric plane
               represented by plane. The geometric plane is the
               set of vectors

                  point   +   s * span1   +   t * span2

               where s and t are real numbers. 'point' is the closest
               point in the plane to the origin; this point is
               always a multiple of the plane's normal vector.
               'span1' and 'span2' are an orthonormal pair of
               vectors. 'point', 'span1', and 'span2' are mutually
               orthogonal.

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 a normal vector from a plane and a
      ;; point in a plane.
      ;;
      normal = [ -1.d,  5.d  , -3.5d ]
      point  = [  9.d, -0.65d, -12.d ]

      ;;
      ;; Create a SPICE plane from the vectors.
      ;;
      cspice_nvp2pl, normal, point, plane

      ;;
      ;; Calculate a point in the plane, and
      ;; two spanning vectors in the plane such that
      ;; the point and spanning are mutually orthogonal.
      ;;
      cspice_pl2psv, plane, point, span1, span2

      ;;
      ;; Test point, span1, and span2 orthogonality. The dot
      ;; products of any two vectors should equal zero to
      ;; within round-off.
      ;;
      print, cspice_vdot( point, span1)
      print, cspice_vdot( point, span2)
      print, cspice_vdot( span1, span2)

   IDL outputs for cspice_vdot( point, span1):  -9.3277315e-17

   IDL outputs for cspice_vdot( point, span2):   6.8201565e-17

   IDL outputs for cspice_vdot( span1, span2):   6.2390956e-18

Particulars


   Icy geometry routines that deal with planes use the `plane'
   data type to represent input and output planes.  This data type
   makes the subroutine interfaces simpler and more uniform.

   The Icy routines that produce SPICE planes from data that
   define a plane are:

      cspice_nvc2pl ( Normal vector and constant to plane )
      cspice_nvp2pl ( Normal vector and point to plane    )
      cspice_psv2pl ( Point and spanning vectors to plane )

   The Icy routines that convert SPICE planes to data that
   define a plane are:

      cspice_pl2nvc ( Plane to normal vector and constant )
      cspice_pl2nvp ( Plane to normal vector and point    )
      cspice_pl2psv ( Plane to point and spanning vectors )

   Any of these last three routines may be used to convert this
   routine's output, 'plane', to another representation of a
   geometric plane.

Required Reading


   ICY.REQ
   PLANES.REQ

Version


   -Icy Version 1.0.1, 16-AUG-2010, EDW (JPL)

      Expanded and improved I/O and Particulars sections.

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

Index_Entries


   plane to point and spanning vectors




Wed Apr  5 17:58:02 2017