hat deal with planes use the `plane' 
   data type to represent input and output planes.  This data type 
   makes the subroutine interfaces simpler and more uniform. 
 
   The CSPICE routines that produce CSPICE planes from data that 
   define a plane are: 
 
      <a href="nvc2pl_c.html">nvc2pl_c</a> ( Normal vector and constant to plane ) 
      <a href="nvp2pl_c.html">nvp2pl_c</a> ( Normal vector and point to plane    ) 
      <a href="psv2pl_c.html">psv2pl_c</a> ( Point and spanning vectors to plane )