CLHEP Reference Documentation

00001 // -*- C++ -*-
00002 // $Id: ATan.cc,v 1.4 2003/10/10 17:40:39 garren Exp $ 
00003 #include "CLHEP/GenericFunctions/ATan.hh"
00004 #include "CLHEP/GenericFunctions/Square.hh"
00005 #include <assert.h>
00006 #include <cmath>      // for atan()
00007 
00008 namespace Genfun {
00009 FUNCTION_OBJECT_IMP(ATan)
00010 
00011 ATan::ATan()
00012 {}
00013 
00014 ATan::~ATan() {
00015 }
00016 
00017 ATan::ATan(const ATan & right) 
00018 {  }
00019 
00020 
00021 double ATan::operator() (double x) const {
00022   return atan(x);
00023 }
00024 
00025 
00026 
00027 Derivative ATan::partial(unsigned int index) const {
00028   assert(index==0);
00029 
00030   Square square;
00031   
00032   const AbsFunction & fPrime=1.0/(1.0+square);;
00033   return Derivative(& fPrime);
00034 }
00035 
00036 } // end namespace Genfun