Calculates a rotation matrix from J2000 mean equator (EQJ) to true ecliptic of date (ECT).
This is one of the family of functions that returns a rotation matrix
for converting from one orientation to another.
Source: EQJ = equatorial system, using equator at J2000 epoch.
Target: ECT = ecliptic system, using true equinox of the specified date/time.
Calculates a rotation matrix from J2000 mean equator (EQJ) to true ecliptic of date (ECT).
This is one of the family of functions that returns a rotation matrix for converting from one orientation to another. Source: EQJ = equatorial system, using equator at J2000 epoch. Target: ECT = ecliptic system, using true equinox of the specified date/time.