pl2nvp_c

 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,
SpiceDouble         point   )

```

#### Abstract

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

```
PLANES
```

```
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.
```

```
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.
```

```
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  );
```

```
None.
```

#### Literature_References

```
 `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
```
`Wed Apr  5 17:54:40 2017`