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AxesDefinition.cc
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// Nsubjettiness Package
// Questions/Comments? jthaler@jthaler.net
//
// Copyright (c) 2011-14
// Jesse Thaler, Ken Van Tilburg, Christopher K. Vermilion, and TJ Wilkason
//
// $Id: AxesDefinition.cc 833 2015-07-23 14:35:23Z jthaler $
//----------------------------------------------------------------------
// This file is part of FastJet contrib.
//
// It is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2 of the License, or (at
// your option) any later version.
//
// It is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
// License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this code. If not, see <http://www.gnu.org/licenses/>.
//----------------------------------------------------------------------
#include "AxesDefinition.hh"
FASTJET_BEGIN_NAMESPACE // defined in fastjet/internal/base.hh
namespace contrib {
// Repeatedly calls the one pass finder to try to find global minimum
std::vector<fastjet::PseudoJet> AxesDefinition::get_multi_pass_axes(int n_jets,
const std::vector <fastjet::PseudoJet> & inputJets,
const std::vector <fastjet::PseudoJet> & seedAxes,
const MeasureDefinition* measure) const {
assert(n_jets == (int)seedAxes.size()); //added int casting to get rid of compiler warning
// first iteration
std::vector<fastjet::PseudoJet> bestAxes = measure->get_one_pass_axes(n_jets, inputJets, seedAxes,_nAttempts,_accuracy);
double bestTau = measure->result(inputJets,bestAxes);
for (int l = 1; l < _Npass; l++) { // Do minimization procedure multiple times (l = 1 to start since first iteration is done already)
// Add noise to current best axes
std::vector< PseudoJet > noiseAxes(n_jets, PseudoJet(0,0,0,0));
for (int k = 0; k < n_jets; k++) {
noiseAxes[k] = jiggle(bestAxes[k]);
}
std::vector<fastjet::PseudoJet> testAxes = measure->get_one_pass_axes(n_jets, inputJets, noiseAxes,_nAttempts,_accuracy);
double testTau = measure->result(inputJets,testAxes);
if (testTau < bestTau) {
bestTau = testTau;
bestAxes = testAxes;
}
}
return bestAxes;
}
// Used by multi-pass minimization to jiggle axes with noise range.
PseudoJet AxesDefinition::jiggle(const PseudoJet& axis) const {
double phi_noise = ((double)rand()/(double)RAND_MAX) * _noise_range * 2.0 - _noise_range;
double rap_noise = ((double)rand()/(double)RAND_MAX) * _noise_range * 2.0 - _noise_range;
double new_phi = axis.phi() + phi_noise;
if (new_phi >= 2.0*M_PI) new_phi -= 2.0*M_PI;
if (new_phi <= -2.0*M_PI) new_phi += 2.0*M_PI;
PseudoJet newAxis(0,0,0,0);
newAxis.reset_PtYPhiM(axis.perp(),axis.rap() + rap_noise,new_phi);
return newAxis;
}
LimitedWarning HardestJetAxes::_too_few_axes_warning;
LimitedWarning ExclusiveJetAxes::_too_few_axes_warning;
LimitedWarning ExclusiveCombinatorialJetAxes::_too_few_axes_warning;
std::vector<fastjet::PseudoJet> Manual_Axes::get_starting_axes(int,
const std::vector<fastjet::PseudoJet>&,
const MeasureDefinition *) const {
// This is a function dummy and should never be called
assert(false);
std::vector<fastjet::PseudoJet> dummy;
return dummy;
}
} // namespace contrib
FASTJET_END_NAMESPACE

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