Changeset 35cdc46 in git for external/fastjet/PseudoJet.cc

Timestamp:

Sep 3, 2014, 3:18:54 PM (10 years ago)

Author:

Pavel Demin <demin@…>

Branches:

ImprovedOutputFile, Timing, dual_readout, llp, master

Children:

be2222c

Parents:

5b5a56b

Message:

upgrade FastJet to version 3.1.0-beta.1, upgrade Nsubjettiness to version 2.1.0, add SoftKiller version 1.0.0

File:

• external/fastjet/PseudoJet.cc (modified) (9 diffs)

external/fastjet/PseudoJet.cc

@@ -1 @@
-//STARTHEADER
-// $Id$
-//
-// Copyright (c) 2005-2011, Matteo Cacciari, Gavin P. Salam and Gregory Soyez
+//FJSTARTHEADER
+// $Id: PseudoJet.cc 3565 2014-08-11 15:24:39Z salam $
+//
+// Copyright (c) 2005-2014, Matteo Cacciari, Gavin P. Salam and Gregory Soyez
 //
 //----------------------------------------------------------------------
@@ -13 +13 @@
 //
 //  The algorithms that underlie FastJet have required considerable
-//  development and are described in hep-ph/0512210. If you use
+//  development. They are described in the original FastJet paper,
+//  hep-ph/0512210 and in the manual, arXiv:1111.6097. If you use
 //  FastJet as part of work towards a scientific publication, please
-//  include a citation to the FastJet paper.
+//  quote the version you use and include a citation to the manual and
+//  optionally also to hep-ph/0512210.
 //
 //  FastJet is distributed in the hope that it will be useful,
@@ -25 +27 @@
 //  along with FastJet. If not, see <http://www.gnu.org/licenses/>.
 //----------------------------------------------------------------------
-//ENDHEADER
+//FJENDHEADER
 
 
@@ -176 +178 @@
 // return the product, coeff * jet
 PseudoJet operator* (double coeff, const PseudoJet & jet) {
+  // see the comment in operator*= about ensuring valid rap phi
+  // before a multiplication to handle case of multiplication by
+  // zero, while maintaining rapidity and phi
+  jet._ensure_valid_rap_phi(); 
   //return PseudoJet(coeff*jet.four_mom());
   // the following code is hopefully more efficient
@@ -198 +204 @@
 /// multiply the jet's momentum by the coefficient
 void PseudoJet::operator*=(double coeff) {
+  // operator*= aims to maintain the rapidity and azimuth
+  // for the PseudoJet; if they have already been evaluated
+  // this is fine, but if they haven't and coeff is sufficiently
+  // small as to cause a zero or underflow result, then a subsequent
+  // invocation of rap or phi will lead to a non-sensical result. 
+  // So, here, we preemptively ensure that rapidity and phi
+  // are correctly cached
+  _ensure_valid_rap_phi(); 
   _px *= coeff;
   _py *= coeff;
@@ -261 +275 @@
 
 //----------------------------------------------------------------------
-/// transform this jet (given in lab) into a jet in the rest
-/// frame of prest
+/// transform this jet (given in the rest frame of prest) into a jet
+/// in the lab frame 
 //
 // NB: code adapted from that in herwig f77 (checked how it worked
@@ -288 +302 @@
 
 //----------------------------------------------------------------------
-/// transform this jet (given in the rest frame of prest) into a jet
-/// in the lab frame;
+/// transform this jet (given in lab) into a jet in the rest
+/// frame of prest  
 //
 // NB: code adapted from that in herwig f77 (checked how it worked
@@ -587 +601 @@
 // an Error is thrown if this PseudoJet has no currently valid
 // associated ClusterSequence
-std::vector<PseudoJet> PseudoJet::exclusive_subjets (const double & dcut) const {
+std::vector<PseudoJet> PseudoJet::exclusive_subjets (const double dcut) const {
   return validated_structure_ptr()->exclusive_subjets(*this, dcut);
 }
@@ -598 +612 @@
 // an Error is thrown if this PseudoJet has no currently valid
 // associated ClusterSequence
-int PseudoJet::n_exclusive_subjets(const double & dcut) const {
+int PseudoJet::n_exclusive_subjets(const double dcut) const {
   return validated_structure_ptr()->n_exclusive_subjets(*this, dcut);
 }