or example, you can have this routine treat the longitude 
   of the earth as increasing to the west using the kernel 
   variable assignment 
 
      BODY399_PGR_POSITIVE_LON = 'WEST' 
       
   Normally such assignments are made by placing them in a text 
   kernel and loading that kernel via <a href="furnsh_c.html">furnsh_c</a>. 
 
   The definition of this kernel variable controls the behavior of 
   the CSPICE planetographic routines 
 
      <a href="pgrrec_c.html">pgrrec_c</a> 
      <a href="recpgr