**ACTION:**- Form the rotation matrix corresponding to a given axial vector
(single precision).
**CALL:**`CALL sla_AV2M (AXVEC, RMAT)`

**GIVEN:**-

*AXVEC***R(3)**axial vector (radians)

**RETURNED:**-

*RMAT***R(3,3)**rotation matrix

**NOTES:**- 1.
- A rotation matrix describes a rotation about some arbitrary axis.
The axis is called the
*Euler axis*, and the angle through which the reference frame rotates is called the Euler angle. The axial vector supplied to this routine has the same direction as the Euler axis, and its magnitude is the Euler angle in radians. - 2.
- If AXVEC is null, the unit matrix is returned.
- 3.
- The reference frame rotates clockwise as seen looking along the axial vector from the origin.

Starlink User Note 67

P. T. Wallace

12 October 1999

E-mail:ptw@star.rl.ac.uk