JMath/JLegendre.cc

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#include <string>
#include <iostream>
#include <iomanip>

#include "TRandom3.h"

#include "JMath/JLegendre.hh"
#include "JMath/JMathSupportkit.hh"

#include "JTools/JQuantile.hh"

#include "Jeep/JParser.hh"
#include "Jeep/JMessage.hh"


/**
 * \file
 *
 * Example program to test Legendre polynome.
 * \author mdejong
 */
int main(int argc, char**argv)
{
  using namespace std;
  using namespace JPP;

  const double xmin = -10.0;
  const double xmax = +10.0;

  typedef JLegendre<double>  JLegendre_t;

  unsigned int  numberOfEvents;
  unsigned int  numberOfBins;
  JLegendre_t   f1(xmin, xmax);
  int           debug;

  try {

    JParser<> zap("Example program to test Legendre polynome.");

    zap['n'] = make_field(numberOfEvents)   =  0;
    zap['N'] = make_field(numberOfBins)     = 10;
    zap['L'] = make_field(f1);
    zap['d'] = make_field(debug)            = 3;

    zap(argc, argv);
  }
  catch(const exception &error) {
    FATAL(error.what() << endl);
  }


  map<double, double> data;

  for (unsigned int i = 0; i != numberOfBins; ++i) {

    const double x = xmin + i * (xmax - xmin) / (numberOfBins - 1);

    data[x] = f1(x);
  }

  for (map<double, double>::const_iterator i = data.begin(); i != data.end(); ++i) {
    DEBUG("data: " << FIXED(7,3) << i->first  << ' ' << FIXED(7,3) << i->second << endl);
  }


  const size_t N = 3;

  JLegendre<double, N> g1(data.begin(), data.end());

  for (size_t n = 0; n != N + 1; ++n) {
    STATUS("Legendre: " << setw(2) << n << ' ' << FIXED(7,3) << g1[n] << endl);
  }

  if (numberOfEvents > 0) {

    JQuantile Q;

    for (unsigned int i = 0; i != numberOfEvents; ++i) {

      const double x = gRandom->Uniform(xmin, xmax);
      const double y = f1(x);
      const double z = g1(x);

      Q.put(y - z);
    }

    Q.print(cout);
  }

  return 0;
}