[1368] | 1 | // Nsubjettiness Package
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| 2 | // Questions/Comments? jthaler@jthaler.net
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| 3 | //
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| 4 | // Copyright (c) 2011-14
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| 5 | // Jesse Thaler, Ken Van Tilburg, Christopher K. Vermilion, and TJ Wilkason
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| 6 | //
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| 7 | //----------------------------------------------------------------------
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| 8 | // This file is part of FastJet contrib.
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| 9 | //
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| 10 | // It is free software; you can redistribute it and/or modify it under
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| 11 | // the terms of the GNU General Public License as published by the
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| 12 | // Free Software Foundation; either version 2 of the License, or (at
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| 13 | // your option) any later version.
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| 14 | //
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| 15 | // It is distributed in the hope that it will be useful, but WITHOUT
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| 16 | // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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| 17 | // or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
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| 18 | // License for more details.
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| 19 | //
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| 20 | // You should have received a copy of the GNU General Public License
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| 21 | // along with this code. If not, see <http://www.gnu.org/licenses/>.
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| 22 | //----------------------------------------------------------------------
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| 23 |
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| 24 |
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| 25 | #include "MeasureFunction.hh"
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| 26 |
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| 27 | FASTJET_BEGIN_NAMESPACE // defined in fastjet/internal/base.hh
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| 28 |
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| 29 | namespace contrib{
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| 30 |
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| 31 | ///////
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| 32 | //
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| 33 | // Measure Function
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| 34 | //
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| 35 | ///////
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| 36 |
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| 37 | // Return all of the necessary TauComponents for specific input particles and axes
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| 38 | TauComponents MeasureFunction::result(const std::vector<fastjet::PseudoJet>& particles, const std::vector<fastjet::PseudoJet>& axes) {
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| 39 |
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| 40 | std::vector<double> jetPieces(axes.size(), 0.0);
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| 41 | double beamPiece = 0.0;
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| 42 |
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| 43 | // Calculates the unnormalized sub-tau values, i.e. a std::vector of the contributions to tau_N of each Voronoi region (or region within R_0)
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| 44 | for (unsigned i = 0; i < particles.size(); i++) {
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| 45 |
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| 46 | // find minimum distance; start with beam (-1) for reference
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| 47 | int j_min = -1;
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| 48 | double minRsq;
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| 49 | if (_has_beam) minRsq = beam_distance_squared(particles[i]);
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| 50 | else minRsq = std::numeric_limits<double>::max(); // make it large value
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| 51 |
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| 52 | // check to see which axis the particle is closest to
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| 53 | for (unsigned j = 0; j < axes.size(); j++) {
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| 54 | double tempRsq = jet_distance_squared(particles[i],axes[j]); // delta R distance
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| 55 | if (tempRsq < minRsq) {
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| 56 | minRsq = tempRsq;
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| 57 | j_min = j;
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| 58 | }
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| 59 | }
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| 60 |
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| 61 | if (j_min == -1) {
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| 62 | if (_has_beam) beamPiece += beam_numerator(particles[i]);
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| 63 | else assert(_has_beam); // this should never happen.
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| 64 | } else {
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| 65 | jetPieces[j_min] += jet_numerator(particles[i],axes[j_min]);
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| 66 | }
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| 67 | }
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| 68 |
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| 69 | // Calculates normalization for tau and subTau if _has_denominator is true, otherwise returns 1.0 (i.e. no normalization)
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| 70 | double tauDen = 0.0;
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| 71 | if (_has_denominator) {
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| 72 | for (unsigned i = 0; i < particles.size(); i++) {
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| 73 | tauDen += denominator(particles[i]);
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| 74 | }
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| 75 | } else {
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| 76 | tauDen = 1.0; // if no denominator, then 1.0 for no normalization factor
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| 77 | }
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| 78 |
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| 79 | return TauComponents(jetPieces, beamPiece, tauDen, _has_denominator, _has_beam);
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| 80 | }
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| 81 |
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| 82 | } //namespace contrib
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| 83 |
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| 84 | FASTJET_END_NAMESPACE
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