Index Page pl2nvp_c

A B C D E F G H I J K L M N O P Q R S T U V W X

Procedure Abstract Required_Reading Keywords Brief_I/O Detailed_Input | Detailed_Output Parameters Exceptions Files Particulars Examples | Restrictions Literature_References Author_and_Institution Version Index_Entries

#### Procedure

       void pl2nvp_c ( ConstSpicePlane   * plane,
                       SpiceDouble         normal[3],
                       SpiceDouble         point [3]  )

#### Abstract

       Return a unit normal vector and point that define a specified
       plane.

#### Required_Reading

       PLANES

#### Keywords

       GEOMETRY
       MATH
       PLANE

#### Brief_I/O

       Variable  I/O  Description
       --------  ---  --------------------------------------------------
       plane      I   A CSPICE plane.
       normal,
       point      O   A unit normal vector and point that define plane.

#### Detailed_Input

       plane          is a CSPICE plane.

#### Detailed_Output

       normal,
       point          are, respectively, a unit normal vector and point
                      that define the geometric plane represented by
                      plane.  Let the symbol < a, b > indicate the inner
                      product of vectors a and b; then the geometric
                      plane is the set of vectors x in three-dimensional
                      space that satisfy

                         < x - point, normal >  =  0.

                      point is always the closest point in the input
                      plane to the origin.  point is always a
                      non-negative scalar multiple of normal.

#### Parameters

       None.

#### Exceptions

       Error free.

       1)  The input plane MUST have been created by one of the CSPICE
           routines

              nvc2pl_c ( Normal vector and constant to plane )
              nvp2pl_c ( Normal vector and point to plane    )
              psv2pl_c ( Point and spanning vectors to plane )

           Otherwise, the results of this routine are unpredictable.

#### Files

       None.

#### Particulars

       CSPICE 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 CSPICE routines that produce CSPICE planes from data that
       define a plane are:

          nvc2pl_c ( Normal vector and constant to plane )
          nvp2pl_c ( Normal vector and point to plane    )
          psv2pl_c ( Point and spanning vectors to plane )

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

          pl2nvc_c ( Plane to normal vector and constant )
          pl2nvp_c ( Plane to normal vector and point    )
          pl2psv_c ( Plane to point and spanning vectors )

#### Examples

       1)  Given a plane normal and constant, find a point in
           the plane.  point is the point we seek.

              nvc2pl_c ( normal, const,  &plane );
              pl2nvp_c ( &plane, normal, point  );

#### Restrictions

       None.

#### Literature_References

       [1] `Calculus and Analytic Geometry', Thomas and Finney.

#### Author_and_Institution

       N.J. Bachman   (JPL)

#### Version

       -CSPICE Version 1.0.0, 05-MAR-1999 (NJB)

#### Index_Entries

       plane to normal vector and point

#### Link to routine pl2nvp_c source file pl2nvp_c.c

    Wed Apr  5 17:54:40 2017