cspice_pl2nvp

 Abstract I/O Examples Particulars Required Reading Version Index_Entries
```
```

#### Abstract

```
CSPICE_PL2NVP returns a unit normal vector and point that define a
specified plane.

For important details concerning this module's function, please refer to
the CSPICE routine pl2nvp_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_pl2nvp, plane, normal, point

returns:

normal   a double precision 3-vector

point    a double precision 3-vector

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'.

```

#### 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.

;;
;; A trivial example of plane creation and
;; decomposition. Create a plane via the definition
;; of a plane normal and constant, determine a
;; point in the plane.
;;
plane_norm = [ 2.44d, -5.d/3.d, 11.d/9.d ]
const      = 3.141592654d

;;
;; Construct the SPICE plane.
;;
cspice_nvc2pl, plane_norm, const, plane

;;
;; Convert the plane to a normal vector, point
;; representation, 'point' lies in the plane.
;;
cspice_pl2nvp, plane, norm_vec, point
print, point

IDL outputs:    0.74966576  -0.51206678   0.37551564

```

#### 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.

```

```
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 normal vector and point

```
`Wed Apr  5 17:58:02 2017`