// $Id: EvtDiLog.hh,v 1.1 2009/02/18 21:21:33 ryd Exp $
#ifndef EVTGENBASE_EVTDILOG_HH 
#define EVTGENBASE_EVTDILOG_HH 1

// Include files

/** @namespace EvtDiLog EvtDiLog.hh EvtGenBase/EvtDiLog.hh
 *  Dilogarithm function (replaces CERNLIB DDILOG)
 *
 *  @author Patrick Robbe
 *  @date   2007-01-23
 */
namespace EvtDiLog {
  double DiLog( double x ) ;

  // constants for computation
  static const double Z1 = 1. ;
  static const double HF = Z1 / 2. ;
  static const double PI = 3.14159265358979324 ;
  static const double PI3 = PI * PI / 3. ;
  static const double PI6 = PI * PI / 6. ;
  static const double PI12 = PI * PI / 12. ;
  static const double C[ 20 ]  = {
    0.42996693560813697 ,
    0.40975987533077105 , 
    -0.01858843665014592 ,
    0.00145751084062268 ,
    -0.00014304184442340 ,
    0.00001588415541880 ,
    -0.00000190784959387 ,
    0.00000024195180854 ,
    -0.00000003193341274 ,
    0.00000000434545063 ,
    -0.00000000060578480 ,
    0.00000000008612098 ,
    -0.00000000001244332 ,
    0.00000000000182256 ,
    -0.00000000000027007 ,
    0.00000000000004042 ,
    -0.00000000000000610 ,
    0.00000000000000093 ,
    -0.00000000000000014 ,
    0.00000000000000002 } ;
}
#endif // EVTGENBASE_EVTDILOG_HH