J2000 frame.
 
      #include &quot;SpiceUsr.h&quot;

      SpiceDouble      ra;
      SpiceDouble      dec; 
      SpiceDouble      r;
      SpiceDouble      rotab  [ 3 ][ 3 ]; 
      SpiceDouble      oldvec [ 3 ];
      SpiceDouble      newvec [ 3 ];


      <b>radrec_c</b> ( 1.0, ra, dec, oldvec );

      <a href="pxform_c.html">pxform_c</a> ( &quot;B1950&quot;, &quot;J2000&quot;, 0.0, rotab );

      <a href="mxv_c.html">mxv_c</a>    ( rotab,   oldvec, newvec );
      <a href="recrad_c.html">recrad_c</a