CSPICE_XF2RAV determines the rotation matrix and angular
velocity of the rotation from a state transformation matrix.
For important details concerning this module's function, please refer to
the CSPICE routine xf2rav_c.
xform the 6x6 double precision transformation matrix
between two reference frames
cspice_xf2rav, xform, rot, av
rot the 3x3 double precision rotation matrix between
av the double precision angular velocity 3-vector associated
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.
;; Calculate the state transformation matrix between the J2000
;; and IAU_EARTH reference frames at some ephemeris time et.
cspice_sxform, "J2000", "IAU_EARTH", et, tsipm
;; Calculate the rotation matrix and angular velocity vector
;; between the two frames. As J2000 is an inertial frame, av
;; contains the angular velocity of the Earth.
cspice_xf2rav, tsipm, tpmi, av
cspice_rav2xf inverts the operation of cspice_xf2rav.
-Icy Version 1.0.1, 12-APR-2007, EDW (JPL)
Edit to abstract.
-Icy Version 1.0.0, 16-JUN-2003, EDW (JPL)
State transformation to rotation and angular velocity