1 | #ifndef __CMS_ITERATIVE_CONE__SORT_BY_ET_H__ |
---|
2 | #define __CMS_ITERATIVE_CONE__SORT_BY_ET_H__ |
---|
3 | |
---|
4 | //STARTHEADER |
---|
5 | // $Id: SortByEt.h 859 2012-11-28 01:49:23Z pavel $ |
---|
6 | // |
---|
7 | // Copyright (c) ????-????, CMS collaboration |
---|
8 | // Copyright (c) 2009-2011, Matteo Cacciari, Gavin P. Salam and Gregory Soyez [for the changes listed below] |
---|
9 | // |
---|
10 | //---------------------------------------------------------------------- |
---|
11 | // This file distributed with FastJet has been obtained from the CMS |
---|
12 | // collaboration, revision 1.2 of the EtComparator.h file in CMSSW, |
---|
13 | // see |
---|
14 | // http://cmssw.cvs.cern.ch/cgi-bin/cmssw.cgi/CMSSW/PhysicsTools/Utilities/interface/EtComparator.h?hideattic=0&revision=1.2&view=markup |
---|
15 | // |
---|
16 | // Permission has been granted by the CMS collaboration to release it |
---|
17 | // in FastJet under the terms of the GNU Public License(v2) (see the |
---|
18 | // COPYING file in the main FastJet directory for details). |
---|
19 | // Changes from the original file are listed below. |
---|
20 | // |
---|
21 | // FastJet is free software; you can redistribute it and/or modify |
---|
22 | // it under the terms of the GNU General Public License as published by |
---|
23 | // the Free Software Foundation; either version 2 of the License, or |
---|
24 | // (at your option) any later version. |
---|
25 | // |
---|
26 | // The algorithms that underlie FastJet have required considerable |
---|
27 | // development and are described in hep-ph/0512210. If you use |
---|
28 | // FastJet as part of work towards a scientific publication, please |
---|
29 | // include a citation to the FastJet paper. |
---|
30 | // |
---|
31 | // FastJet is distributed in the hope that it will be useful, |
---|
32 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
---|
33 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
---|
34 | // GNU General Public License for more details. |
---|
35 | // |
---|
36 | // You should have received a copy of the GNU General Public License |
---|
37 | // along with FastJet. If not, see <http://www.gnu.org/licenses/>. |
---|
38 | //---------------------------------------------------------------------- |
---|
39 | //ENDHEADER |
---|
40 | |
---|
41 | // List of changes compared to the original CMS code (revision 1.2 of |
---|
42 | // EtComparator.h) |
---|
43 | // |
---|
44 | // 2009-01-06 Gregory Soyez <soyez@fastjet.fr> |
---|
45 | // |
---|
46 | // * Extracted (only) NumericSafeGreaterByEt from the CMS code |
---|
47 | // and adapted it to act on PseudoJet rather than CMS types |
---|
48 | // for 4-momenta |
---|
49 | // * Put the code in a fastjet::cms namespace |
---|
50 | |
---|
51 | #include <limits> |
---|
52 | #include <fastjet/internal/base.hh> |
---|
53 | |
---|
54 | FASTJET_BEGIN_NAMESPACE |
---|
55 | |
---|
56 | namespace cms{ |
---|
57 | |
---|
58 | template <class T> |
---|
59 | struct NumericSafeGreaterByEt { |
---|
60 | typedef T first_argument_type; |
---|
61 | typedef T second_argument_type; |
---|
62 | bool operator()(const T& a1, const T& a2) { |
---|
63 | // FastJet::PseudoJet does not provide a direct access to Et2 |
---|
64 | // Plus, we want it to be computed in the same way as in the CMS |
---|
65 | // code (actually the Root code that is used by CMS) |
---|
66 | double et1 = a1.Et(); |
---|
67 | double et2 = a2.Et(); |
---|
68 | |
---|
69 | // now we can come back to the CMS code |
---|
70 | return |
---|
71 | fabs (et1-et2) > std::numeric_limits<double>::epsilon() ? et1 > et2 : |
---|
72 | fabs (a1.px()-a2.px()) > std::numeric_limits<double>::epsilon() ? a1.px() > a2.px() : |
---|
73 | a1.pz() > a2.pz(); |
---|
74 | } |
---|
75 | }; |
---|
76 | |
---|
77 | } // namespace cms |
---|
78 | |
---|
79 | FASTJET_END_NAMESPACE |
---|
80 | |
---|
81 | |
---|
82 | #endif // __CMS_ITERATIVE_CONE__SORT_BY_ET_H__ |
---|