polylog_test.cc

//
// APFEL++ 2017
//
// Author: Valerio Bertone: valerio.bertone@cern.ch
//
 
#include <apfel/apfelxx.h>
 
int main()
{
  const double xx = 0.4;
 
  double *x   = new double;
  int    *nw  = new int;
  int    *wn1 = new int;
  int    *wn2 = new int;
  *x   = xx;
  *nw  = 5;
  *wn1 = -1;
  *wn2 = 1;
 
  // HPLOG all at once up to weight 5
  double *H = new double[363];
  apfel::apf_hplog_(x, nw, &H[0], &H[3], &H[12], &H[39], &H[120], wn1, wn2);
 
  std::cout << " x = " << xx << std::endl;
  std::cout << "                        "
            << "   HPOLY        "
            << "   HPLOG_       "
            << std::endl;
  std::cout << std::scientific;
  std::cout << "HPL({-1}, x)          = " << apfel::hpoly({-1}, 0.4)          << ",\t" << H[apfel::HPLogMap({-1})]          << std::endl;
  std::cout << "HPL({0,1}, x)         = " << apfel::hpoly({0,1}, 0.4)         << ",\t" << H[apfel::HPLogMap({0,1})]         << std::endl;
  std::cout << "HPL({-1,0,0}, x)      = " << apfel::hpoly({-1,0,0}, 0.4)      << ",\t" << H[apfel::HPLogMap({-1,0,0})]      << std::endl;
  std::cout << "HPL({-1,-1,1,0}, x)   = " << apfel::hpoly({-1,-1,1,0}, 0.4)   << ",\t" << H[apfel::HPLogMap({-1,-1,1,0})]   << std::endl;
  std::cout << "HPL({-1,-1,1,0,1}, x) = " << apfel::hpoly({-1,-1,1,0,1}, 0.4) << ",\t" << H[apfel::HPLogMap({-1,-1,1,0,1})] << std::endl;
  std::cout << "\n";
 
  // Performance test
  const double nc = 1000;
  apfel::Timer t;
  for (int i = 0; i < nc; i++)
    apfel::hpoly({-1,-1,1,0,1}, 0.4);
  std::cout << "Calling HPOLY  " << nc << " times... ";
  t.stop();
 
  t.start();
  for (int i = 0; i < nc; i++)
    apfel::apf_hplog_(x, nw, &H[0], &H[3], &H[12], &H[39], &H[120], wn1, wn2);
  std::cout << "Calling HPLOG_ " << nc << " times... ";
  t.stop();
  std::cout << "\n";
 
  // Testing Nielsen's polylog against Li2
  std::cout << "Li2(x) = " << apfel::dilog(xx) << std::endl;
  std::cout << "S_{1,1}(x) = " << apfel::wgplg(1, 1, xx) << std::endl;
  std::cout << "\n";
 
  delete x;
  delete nw;
  delete wn1;
  delete wn2;
  delete[] H;
  return 0;
}