def ra_dec_to_cartesian(<EOL>self,<EOL>ra,<EOL>dec):
self.log.info('<STR_LIT>')<EOL>ra = self.ra_sexegesimal_to_decimal(<EOL>ra=ra<EOL>)<EOL>dec = self.dec_sexegesimal_to_decimal(<EOL>dec=dec<EOL>)<EOL>ra = math.radians(ra)<EOL>dec = math.radians(dec)<EOL>cos_dec = math.cos(dec)<EOL>cx = math.cos(ra) * cos_dec<EOL>cy = math.sin(ra) * cos_dec<EOL>cz = math.sin(dec)<EOL>cartesians = (cx, cy, cz)<EOL>self.log.info('<STR_LIT>')<EOL>return cartesians<EOL>
*Convert an RA, DEC coordinate set to x, y, z cartesian coordinates*

        **Key Arguments:**
            - ``ra`` -- right ascension in sexegesimal or decimal degress.
            - ``dec`` -- declination in sexegesimal or decimal degress.

        **Return:**
            - ``cartesians`` -- tuple of (x, y, z) coordinates

        ..  todo::

            - replace calculate_cartesians in all code

        **Usage:**

            .. code-block:: python 

                from astrocalc.coords import unit_conversion
                converter = unit_conversion(
                    log=log
                )
                x, y, z = converter.ra_dec_to_cartesian(
                    ra="23 45 21.23232",
                    dec="+01:58:5.45341"
                )
                print x, y, z

                # OUTPUT: 0.9973699780687104, -0.06382462462791459, 0.034344492110465606