
ACTION:
 Form the rotation matrix corresponding to a given axial vector (double precision).

CALL:
CALL sla_DAV2M (AXVEC, RMAT)
GIVEN:
AXVEC  D(3)  axial vector (radians) 

RETURNED:
RMAT  D(3,3)  rotation matrix 


NOTES:


(1)
 A rotation matrix describes a rotation about some arbitrary axis, called the Euler
axis. The axial vector supplied to this routine has the same direction as the Euler axis,
and its magnitude is the amount of rotation 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.