cspice_vrotv

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

#### Abstract

```
CSPICE_VROTV rotates a double precision 3-vector about a specified
axis vector by a specified angle (measured in radians) then
returns the rotated vector.

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

```

#### I/O

```
Given:

v       an arbitrary double precision 3-vector to rotate.

axis    a double precision 3-vector defining the axis about which
to rotate 'v'.

theta   a double precision scalar angle measured in radians through
which you rotate 'v' about 'axis'.

the call:

cspice_vrotv, v, axis, theta, r

returns:

r   a double precision 3-vector, the result of rotating 'v' about
'axis' through an angle of 'theta'.

```

#### 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.

;;
;; Given an axis of rotation and an angle of rotation.
;;
axis  = [ 0.d, 0.d, 1.d]
theta = cspice_pi()/2.d0

;;
;; Perform rotations on various vectors...
;;

Example(1):

v1 = [ 1.d, 2.d, 3.d ]
cspice_vrotv, v1, axis, theta, r1
print, r1

IDL outputs:

-2.0000000    1.0000000      3.0000000

Example(2):

v2 = [ 1.d, 0.d, 0.d ]
cspice_vrotv, v2, axis, theta, r2
print, r2

IDL outputs:

6.1232340e-17  1.0000000      0.0000000

Example(3):

v3 = [ 0.d, 1.d, 0.d ]
cspice_vrotv, v3, axis, theta, r3
print, r3

IDL outputs:

-1.0000000     6.1232340e-17  0.0000000

Where 6.1232340e-17 equates to 0.d with regards to double precision
round-off.

```

```
None.

```

```
ICY.REQ
ROTATION.REQ

```

#### Version

```
-Icy Version 1.0.3, 13-JUN-2011, EDW (JPL)

Edits to comply with NAIF standard for Icy headers.

-Icy Version 1.0.2, 13-JUN-2010, EDW (JPL)

Minor edit to code comments eliminating typo.

-Icy Version 1.0.1, 17-APR-2008, EDW (JPL)

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

```

#### Index_Entries

```
`Wed Apr  5 17:58:04 2017`