1 Release Notes
for FastJet
2 -------------------------
4 ================================================================
5 Summary of changes from v3.0.6 -> v3.1.0-beta.1: 2014-08-15
6 ================================================================
7 * Significant speed improvements (x1.5-10) for large N (few thousand-10^5)
8 * FASTJET_VERSION_NUMBER preprocessor symbol, for easy in-code version testing
10 * Native particle-mass support in PU estimation (rho_m())
11 * Subtraction can use rho_m (set_use_rho_m()) and force m>0 (set_safe_mass())
14 * Fixed
long-standing issue with coincident points in NlnN strategies
15 * Other small additions and changes include:
16 *
Selector::sum(particles) to get 4-vector sum of particles that pass selector
17 * pruned_jet.structure_of<
Pruner>() has Rcut() and zcut() functions
18 * easy copying of Recombiner info: jet_def1.set_recombiner(jet_def2)
19 * Various bug-fixes, build-system tweaks (e.g. default -O2 instead of -O3)
21 ================================================================
22 Summary of changes from v3.0.5 -> v3.0.6: 2013-10-29
23 ================================================================
24 This is a minor maintenance release. Main changes:
25 * fixed compilation issues for two plugins under OS X 10.9 (Mavericks)
29 ================================================================
30 Summary of changes from v3.0.4 -> v3.0.5: 2013-09-16
31 ================================================================
32 This is a minor maintenance release. Main changes:
33 * modified include guards, to solve coexistence issue for fjcore
34 * resolved (bogus) compiler warning about uninitialised variables
35 * added an example event file that was missing from the distribution
37 ================================================================
38 Summary of changes from v3.0.3 -> v3.0.4: 2013-06-05
39 ================================================================
41 This is a minor maintenance release. Changes include:
42 * dummy init of
PseudoJet rapidity to avoid warnings with some configs.
43 * minor code structure adjustments to allow for release of fjcore
44 * inclusion of SISCone 2.0.6
46 ================================================================
47 Summary of changes from v3.0.2 -> v3.0.3: 26/06/12
48 ================================================================
50 This is a bug-fix release, fixing
52 * compilation issues with g++-4.7 and clang
53 * issue of missing documentation figures in the tarball
54 * issue with the --enable-extra-warnings flag in configure
56 ================================================================
57 Summary of changes from v3.0.1 -> v3.0.2: 17/01/12
58 ================================================================
60 This is a bug-fix release, including
62 * small fixes to the build system and fastjet-config
63 * further licence clarifications
64 * user can force early printing of banner with
ClusterSequence::print_banner()
65 * included SISCone 2.0.5 (with small modifications to the build system)
67 ================================================================
68 Summary of changes from v3.0.0 -> v3.0.1: 25/11/11
69 ================================================================
71 Version 3.0.1 includes further reorganisation of the manual (version to
72 appear on arXiv), and a number of small additional changes, including :
74 *
PseudoJet now also has a pt() member function for transverse momentum
75 * minor speed improvements (very low N + strategy choice for N ~ 20-50)
76 * elimination of many compilation warnings found with -Wextra -Wshadow
77 * clarification of licenses for many of the plugins + new plugin banners
80 ================================================================
81 Summary of changes from v2.4.4 -> v3.0.0: 09/10/11
82 ================================================================
84 Changes relative to the 2.4.x series include:
86 Addition of FastJet tools:
88 * Filtering, trimming, pruning and a few boosted
object taggers as
89 part of a new native "Transformers" framework for post-clustering
92 * New background estimation and subtraction interface, with
97 * Enhancement of the
PseudoJet class so that jets are now aware of their
98 internal structure (e.g. one can use jet.constituents()).
99 * It is possible to associate arbitrary user information with a
PseudoJet.
100 * Selectors, which allow easy communication of cuts across different functions
104 * Improved doxygen and examples
105 * aids for easier memory management
106 * elimination of the R<pi/2 restriction on native jet algorithms
108 * new plugins (GridJet and two D0RunICone plugins)
109 * enhanced fortran wrappers
111 Interface modifications (May break backwards compatibility):
113 * by default a
JetDefinition is initialised to undefined_jet_algorithm
114 instead of kt_algorithm with a radius of 1.
115 *
JetDefinition::DefaultRecombiner sets the user index of the result
116 of the recombination to -1 (the default for a
PseudoJet;
117 previously was being set to 0)
118 * ghosts are placed more sensibly in 3.0 than in the 2.X series;
119 call ghost_area_spec.set_fj2_placement(true) to reinstate old behaviour
120 * CS::exclusive_subjets used to silently return fewer subjets than
121 requested if there were too few particles in a jet; to be
122 consistent with exclusive_jets(...) it now throws an exception;
123 use exclusive_jets_up_to(...) and exclusive_subjets_up_to(...) to
125 * ATLASCone and TrackJet plugins use stable_sort instead of sort for
126 more stable behaviour across architectures and compiler versions;
127 this can change clustering results in events with degeneracies.
128 * some legacy headers have been removed (include/FjPseudoJet.hh and
129 include/FjClusterSequence.hh), and some classes are deprecated:
132 and CircularRange (use
Selector instead); see appendix G in manual
133 for further small removals.
135 Configure modifications
137 * the plugins are by default built in a single 'libfastjetplugin'
138 library. This is transparent if you use the fastjet-config
139 script. The previous behaviour (each plugin in its own library)
140 can be recovered by passing the --disable-monolithic option to
142 * an additional library, libfastjettools, contains tools like
143 boosted
object taggers, filters, etc. It is included by default
144 with "fastjet-config --libs"
147 New features relative to 3.0beta1:
149 * addition of
Pruner class
154 Bug fixes and other changes relative to 3.0beta1:
156 * JetMedianBackgroundEstimator::set_particles(...) no longer resets other parameters
157 * fixed issue with persistency of internal recombiner in
Filter
159 jet def) and also CS::set_jet_algorithm(...), CS::set_jet_def(...)
162 ================================================================
163 Summary of changes from v3.0beta1 -> v3.0.0: 09 October 2011
164 ================================================================
166 - addition of
Pruner class
171 Bug fixes and other changes
172 - JetMedianBackgroundEstimator::set_particles(...) no longer resets other parameters
173 - fixed issue with persistency of internal recombiner in
Filter
174 - removed deprecated
ClusterSequence constructor with R (rather than jet def)
175 and also CS::set_jet_algorithm(...), CS::set_jet_def(...)
177 ================================================================
178 Summary of changes from v3.0alpha3 -> v3.0beta1: 10 August 2011
179 ================================================================
181 - Reorganised background estimation to have a JetMedianBackgroundEstimator
183 [v3.0alpha3 programs should replace BackgroundEstimator
184 -> JetMedianBackgroundEstimator, and use a new order of constructor arguments]
186 - added a
TopTaggerBase and a Johns Hopkins top tagger (JHTopTagger)
188 delete_recombiner_when_unused()
189 - improved
Filter (for area and recombiner support, also works with a subtractor)
190 - added a --config flag to fastjet-config
192 Bug fixes and other changes
193 - some speed gains in the default recombiner
194 - TrackJet and ATLASCone now use stable_sort (can change results;
195 makes results stable across machine architectures & compilers, cf BUGS)
196 - fixed bugs in Voronoi areas (as in v.2.4.4)
197 - fixed bugs in handling of empty areas in background estimator (as in 2.4.4)
198 - renamed SelectorMXXX -> SelectorMassXXX
200 - exclusive_[sub]jets(njets) now consistenty throws an error if it
201 can't deliver njets; exclusive_[sub]jets_upto(njets) gives up to njets
206 - reorganisation of substantial parts of the manual
209 ================================================================
210 Summary of changes from v3.0alpha2 -> v3.0alpha3: 03 June 2011
211 ================================================================
215 *
Subtractor: subtract the jet using a BackgroundEstimator
218 * NSubjettinessTagger: 2-pronged tagger based on rest-frame 2-subjettiness
219 *
CASubJetTagger: 2-pronged tagger based on maximal distance in jet history
220 *
Filter updated from alpha2 (bug fixes & new constructors)
221 NB: examples 11 (boosted Higgs) and 12 (
Filter) illustrate usage.
223 - CS::delete_self_when_unused() allows it to handle its own memory management
228 the jets from an old sequence as they are transferred to the new one
229 - fortran interface now has basic area functionality
231 Changes to features introduced in alpha2 and alpha1:
232 - Numerous changes to BackgroundEstimator
233 * it allows manual encoding of rapidity dependence;
234 * it can calculate density of quantities other than pt;
235 * it has additional constructors, plus methods to reset its
ClusterSequence, etc.
236 * its sigma() now properly handles finite numbers of jets (+ other bug fixes).
237 - jet.pieces() for a jet from a clustering now returns the two parents
238 - various changes to behaviour of a jet's structural calls; see new table in doc
239 - PseudoJet::extra_properties<...>() -> PseudoJet::structure_of<...>() (cf example 12)
240 - join(...) can now include a recombiner argument; it also now supports areas
241 -
Selector::count(jets) to know how many pass a cut (also new:
Selector::sift)
244 - by default a PseudoJet is constructed with zero momentum
246 - efficiency improvements in PtYPhiM and ghost generation
248 retained, but deprecated.
249 - added an example (09) to illustrate how to add user-info to a PseudoJet
250 - doxygen output now configured with an internal search engine
253 - the default recombiner used to set the user_index to the non-default
254 value of 0. Now it sets it to the default (-1).
255 - fixed crashes of VoronoiAreas for particles on a grid (also in 2.4.3)
258 ================================================================
259 Summary of changes from v3.0alpha1 -> v3.0alpha2: 10 March 2011
260 ================================================================
263 - two jets, a and b can now be joined: PseudoJet c = join(a,b),
264 intended to facilitate packaging the result of substructure tools;
265 individual pieces can be recovered with c.pieces();
267 - New fastjet/tools/
Filter.hh provides a unified interface to filtering and trimming
268 - New very preliminary fastjet/tools/BackgroundEstimator.hh to provide
269 a more flexible interface to estimation of backgrounds (removal of
271 - a few extra Selectors
273 Changes to features introduced in alpha1:
275 -
Selector::relocate(...) and is_relocatable() renamed to
276 Selector::set_reference(...) and takes_reference()
277 - PseudoJet::ExtraInfo has been renamed PseudoJet::UserInfoBase and
278 corresponding access functions are now called set_user_info(...), etc.
280 Other changes and fixes
281 - some legacy headers removed
282 - bug fixes in NlnNCam strategies for R>pi
284 ===========================================================
285 Summary of changes from v2.4.X -> v3.0alpha1: 27 January 2011
286 ===========================================================
288 This is an alpha release, previewing some of the new features that are
289 expected to be available in FastJet version 3. Interfaces of new
290 features may yet evolve.
293 - Several extensions to PseudoJet:
294 * it now knows what ClusterSequence it belongs to
295 * info about internals of jets can be accessed e.g. as jet.constituents()
296 * it now has a virtual destructor + other support for classes derived from PseudoJet
297 * new facilities for associating user info with a jet (see PseudoJet::ExtraInfo)
298 * some of these features make use of a new
SharedPtr class
299 (intended mainly for advanced users)
300 similar to C++0x std::shared_ptr
301 * calculation of phi and rapidity (cached) only on request
302 - R can now be taken larger than pi/2 for natively coded jet algorithms
303 - Addition of "
Selector" tools through
#include "fastjet/tools/Selector.hh"
304 - New plugin
for D0RunICone (code contributed by Lars Sonnenschein)
305 - Improvements to fortran wrapper (access to SISCone, jet constituents, etc.)
308 - fixed issue with inconsistent returned sign in PseudoJet::delta_phi_to(...)
310 Other notable changes:
311 - Revamping of examples
312 - by default all plugins are now packaged into libfastjetplugins.
313 Note that "external" libraries like libsiscone are still separate.
314 - Significant improvements to doxygen documentation
316 ===========================================================
317 Summary of changes from v2.4.1 -> v2.4.2: 26 February 2010
318 ===========================================================
319 - exclusive_ymerge_max(...) was not working; now fixed
322 optimisation flags now changed just for D0 code so that 32 bit gives same
324 - changes to configure.ac to better handle fortran compiler checks
325 - removed some orphan/redundant code that was generating compilation warnings
326 - added an "--enable-monolithic" option to ./configure which causes
327 all plugins to be placed in a single library (except SISCone)
328 - added a "--list-plugins" option to fastjet-config
330 =======================================================
331 Summary of changes from v2.4.0 -> v2.4.1: 29 May 2009
332 =======================================================
334 Fixes to the build system
335 -------------------------
336 - Included SISCone 2.0.1 (shared libs now enabled by default in
337 SISCone too, and other small fixes)
338 - Fixed platform-dependent failures during make check
339 - Fixed gcc 4.4 compatibility issues (missing headers)
340 - Fixed a problem on Mac OS X with the arguments provided by
341 "fastjet-config --libs" (--rpath versus -rpath).
342 - fastjet-config has new optional arguments (--rpath=no, --runpath)
343 related to finding shared libraries at runtime on linux.
344 Run fastjet-config without any arguments for more info.
345 To instead use static libraries, either configure with the
346 --disable-shared option, or use fastjet-config with the --shared=no option.
347 - fastjet-config can now take --cxxflags and --libs in a single invocation
348 - With --cxxflags, fastjet-config now returns the minimal required set of arguments
349 - Various other small mods (better fortran support, standardisation, ...)
350 [thanks to Andy Buckley and David Grellscheid for suggestions]
354 - Added a fortran wrapper for pp sequential recombination algorithms
355 - Fixed issue in median rho estimation when some jets have zero area
356 - Expanded descriptions that are returned by ATLAS/TrackJet/CMS plugins
357 - Warnings are no longer given when using exclusive jets with
358 Cam/Aachen and certain e+e- algorithms (the warnings were misleading)
359 - Small fixes to the manual
361 =======================================================
362 Summary of changes from v2.3.X -> v2.4.0: 17 April 2009
363 =======================================================
369 - added implementation of generalised kt algorithm (genkt_algorithm) for pp
370 - added D0RunIICone plugin [--enable-d0runiicone at configure time]
371 - added ATLASCone Plugin [--enable-atlascone at configure time]
373 - added TrackJet Plugin (used by CDF in UE studies)
374 [--enable-trackjet at configure time]
376 Introduction of e+e- algorithms
377 -------------------------------
379 - added an implementation of the e+e- kt algorithm (ee_kt_algorithm),
381 - added JADEPlugin for the JADE algorithm (see the ChangeLog or header
384 e+e- and other spherical environments.
385 - native implementation of generalised kt algorithm for e+e- (ee_genkt_algorithm)
386 [also provides access to e+e- form of anti-kt alg, conical jets on a sphere]
387 - added
JadePlugin for the e+e- Jade algorithm
392 - added NestedDefs plugin for daisy-chaining multiple jet definitions
393 [still under testing; API may change in the future]
397 - added subjet functions for viewing jet at particular dcut, etc.
398 - added access to exclusive jets based on ycut as well as dcut (for e+e-)
401 use in background estimation
402 - added class
NNH to help users implement algorithms with
403 user-chosen distance measure (see
JadePlugin for an example)
405 Interface modifications
406 -----------------------
407 - removed default value of 0.5 for overlap_threshold in
410 *** may break backwards compatibility ***
412 - a
JetDefinition(jet_alg) constructor, without an R value, is no
413 longer legal, except when jet_alg is ee_kt_algorithm (it has no R).
415 *** may break backwards compatibility ***
417 - in SISCone, new way of accessing the information about pass at which
418 a jet was found (old method retained for 2.4, but now deprecated)
421 Configure modifications
422 -----------------------
423 - added --enable-allplugins and --enable-allcxxplugins options, to
424 avoid having to specify a
long list of individual plugins
425 - shared libraries are now enabled by default
433 -----------------------
434 - added support for CGAL 3.4 (for non-standard locations, specify
435 --with-cgaldir at configure time)
436 - removed restriction that fastjet throws exception on empty events
437 - added an example that illustrates the use of subjet techniques for
438 a boosted Higgs->b+bbar search
442 - add CMSIterativeCone Plugin
446 =======================================================================
447 Summary of changes from v2.3.3 -> v2.3.4 (bug fix release): 15 Aug 2008
448 ==========================================================
450 - fixed infinite-loop bug in JetClu plugin on certain rare events
452 - fixed compatibility issues of certain example programs with g++-4.3
454 - incorporated SISCone 1.3.3 with similar g++-4.3 fixes
456 =======================================================================
457 Summary of changes from v2.3.2 -> v2.3.3 (bug fix release): 28 Apr 2008
458 ==========================================================
460 - fixed missing installation of .../config_auto.h
462 - fixed missing typename in .../SearchTree.hh
464 =======================================================================
465 Summary of changes from v2.3.1 -> v2.3.2 (bug fix release): 03 Apr 2008
466 ==========================================================
468 - fixes to propagation of CXXFLAGS through the build chain
470 - small change in Voronoi area code to fix crashes on regular
471 (calorimeter) layouts of momenta
473 - small change in active areas code to fix crashes on algorithms that
474 do not cluster all particles
476 - eliminated "using namespace std" that had accidentally been left in
477 certain area header files
479 - incorporation of SISCone 1.3.2 with fixes for inappropriate public
480 symbols and to build framework
483 ======================================================================
484 Summary of changes from v2.3.0 -> v2.3.1 (bug fix release)
485 ==========================================================
487 - Fixed compilation issues under windows VC7.1 (reported by
488 I. Belyaev); also included SISCone 1.3.1 with similar fixes.
490 - Fixed speed issue under optimized compilation of CDF MidPoint plugin
491 for 32 bit architectures that had arisen subsequent to the switch to
492 autotools with its common optimization settings.
494 - Fixed "make check" failure with the --disable-siscone option.
496 - Fixed crash in exclusive_dmerge(njets) for njets=0 (reported by P. Lenzi)
499 ======================================================================
500 Summary of changes from v2.1.0 (previous stable release) to v2.3.0
501 ===================================
503 - added the anti-kt algorithm (LPTHE-07-03), which is a sequential
504 recombination algorithm that gives conical jets.
506 - Added Passive and Voronoi areas, and new common class for accessing
509 - switched to autotools for compilation and installation:
510 ./configure --prefix=...
512 make check [optional]
515 NB: users should no longer include fastjet-2.x.y/Makefile
516 when building their own programs, and instead should use
517 g++ -c file.cc `fastjet-config --cxxflags`
518 g++ file.o `fastjet-config --libs --plugins`
520 - plugin include files are now to be accessed with fastjet/ in
522 #include "fastjet/SISConePlugin.hh"
523 A simple #include
"SISConePlugin.hh" is now obsolete but will
524 continue to work through 2.x
529 - New facilities for navigating the cluster sequence (has_parents,
530 has_child and has_partner members of ClusterSequence)
532 - other bug fixes and small enhancements (including SISCone-1.3.0,
533 improvements to plugin facilities).
535 See individual beta-releases below for more information, as well as
539 ======================================================================
540 Changes from v2.2beta0 to v2.3-beta0
541 ===================================
543 - switched to autotools
for compilation and installation;
545 - old build procedure still available
for now, with files called
546 makefile.static (make -f makefile.static);
548 test-script.sh has been renamed test-
static.sh and builds and
549 tests
using the old procedure.
551 - plugins include files are now to be accessed with fastjet/ in
553 #include
"fastjet/SISConePlugin.hh"
555 For backwards compatibility, the old access method will
continue
556 to work throughout v2.x, i.e.
557 #include
"SISConePlugin.hh"
559 - added PseudoJet::reset(...) functions to reset the contents of a
562 - added fastjet_version_string()
564 - added a function PtYPhiM(...) that returns a PseudoJet with the
565 given py, rapidity , phi and mass. Defined in PseudoJet.hh
567 - added a directory fortran_wrapper/ to illustrate how to access
570 - some small bug fixes in the CDF midpoint code
573 ======================================================================
574 Changes from v2.1.0 to v2.2beta0
575 ===============================
577 - added the anti-kt algorithm (LPTHE-07-03)
579 - Provided a new common class for accessing all different types of
582 - added functionality for Passive areas and Voronoi areas.
583 Areas are now defined much in the same way as jets, via an
586 sweepline code for calculating the Voronoi diagram and so does not
587 require CGAL to be installed (it still is needed for NlnN kt
591 of the rapidity-azimuth ranges over which to study jet areas
592 and possibly perform noise subtraction
594 - added facilities for navigating the cluster sequence (has_parents,
595 has_child and has_partner members of ClusterSequence)
597 - changed plugin base class, so that it now includes R() virtual
598 member, and modified the various plugins to account for this.
600 - modified the plugin interface to provide facilities to help with
603 - included SISCone-1.2.0 rather than 1.1.1.
605 - adapted SISCone plugin to the 1.2.0 release of SISCone --
main
606 changes are facilities and improvements related areas: some speed
607 improvements on the split-merge (relevant for active areas) and a
608 fairly efficient way of running passive areas.
610 - added ClusterSequence::print_jets_for_root(...) and a corresponding root
611 script (example/root/jet-plots.C), so as to provide a crude
615 ======================================================================
616 Summary of
main changes from v2.0.0 to v2.1.0
617 =============================================
619 - added plugin structure for external jet finders.
621 - included plugins for SISCone, CDFMidPoint, CDFJetClu, PxCone (with
622 extensions for MidPoint and bug fixes for PxCone relative to public
625 - introduced option of control over recombination scheme, with a
628 - added description() member function to
JetDefinition class, so
629 that you can get a (
string) summary of what you're running!
631 - changed the default number of repeats in
ActiveAreaSpec to 1 (which
632 is sufficient for most purposes).
634 For further details, see the changes listed in detail below.
636 ======================================================================
637 Changes from v2.1.0b4 to v2.1.0
638 ===============================
640 - corrected bug in test-script.sh
642 - removed PxCone from default tests and from
643 plugins/usage_examples/many_algs_example.cc (to avoid fortran
646 ======================================================================
647 Changes from v2.1.0b3 to v2.1.0b4
648 =================================
650 FastJet modifications
651 ---------------------
653 - default number of repeats for the active area specification has been
654 changed from 5 to 1 (the latter goes fast, but note that it provides
655 a zero error estimate for the area).
660 - adapted plugin to accomodate new scale for use in the SISCone
661 split-merge (pttilde), with a corresponding change of interface.
663 Changed default number of passes for SISCone to 0.
665 - Added the pttilde scale choice to the CDF plugin.
669 ======================================================================
670 Changes from v2.1.0b2 to v2.1.0b3
671 =================================
676 - methods for estimating the underlying now have the option of using
677 area_4vector rather than the plain area
682 - area_4vector is now calculated with the same recombination scheme as
685 - massless recombination schemes now work correctly on particles with
688 - PseudoJet::phi_std() returned wrong result for phi < pi -- thanks to
689 Oscar Stal for pointing this out.
694 - the plugin mechanism now allows a plugin to add "extra" information
695 to the ClusterSequence, essentially by providing an auto_ptr to a
696 class derived from (the new) ClusterSequence::Extras; an example of
697 this has been implemented with siscone (
SISConeExtras) which allows
698 a user to access the initial (stable) protocones.
700 - included new siscone version (1.1) which uses transverse mass (mt) rather
701 than pt in the split-merge procedure, to address an IR problem in
702 events where the hadronic part conserves momentum -- this can have
703 an effect on some physical distributions; the siscone update also
704 addresses issues with collinear safety and co-circular points.
706 - included bug fixes to pxcone regarding 2pi periodicity when
709 - modified the version of the CDF midpoint cone code so as to allow it
710 to use mt and Et as the parameters in the split--merge step.
712 ======================================================================
713 Changes from v2.1.0b1 to v2.1.0b2
714 =================================
719 - included new siscone version which solves the memory-leak problem
724 - added sample output from the test-script as test-script-output-orig.txt
726 ======================================================================
727 Changes from v2.1.0b0 to v2.1.0b1
728 =========================
733 - added the SISCone plugin and the beta version of the siscone code
734 (authored by Soyez & Salam)
739 - removed extraneous semicolons after functions that were causing
740 problems on some compilers.
745 - Added COPYING file with GPL license
747 ======================================================================
748 Changes from v2.0 to v2.1 (beta0)
749 =========================
754 - introduced option of control over recombination scheme, with a
756 to the
JetDefinition constructor) and also the possibility of an
757 externally defined recombination scheme.
759 - introduced a "plugin" facility for alternative jet finders, via an
764 Plugins are to be provided as classes derived from this,
765 implementing the relevant virtual functions (see manual and examples
768 - introduced "description" member function for the
JetDefinition
769 class, which returns a (std::
string) textual description of the
772 - provided plugins for CDF JetClu, CDF Midpoint, PxCone code; the
773 plugins, the code they interface to and example programs are to be
774 found in the new plugins/ directory.
776 - added ClusterSequence::unclustered_particles() a vector containing
777 the unclustered particles (relevant for some plugin algorithms).
782 - introduced PseudoJet::squared_distance (does same as "plain_distance")
789 - in the documentation, replaced eta -> y, to make it clear that it's
790 rapidity and not pseudorapidity that is being used throughout. Some
791 internal code continues to use variables called "eta" -- but these
792 are actually proper rapidity.
795 ======================================================================
796 Changes from v1.0 to v2.0
797 =========================
802 - the longitudinally invariant inclusive Cambridge/Aachen jet finder
805 Note that the exclusive jets extraction for the Cambridge jet-finder
806 does not provide the definition as given in the original Cambridge
807 paper. See the documentation for further details
809 - classes have been introduced for running jet clustering and
810 simultaneously collecting information about the area of each jet.
811 The base class specifying the functionality is
815 itself derived from ClusterSequence.
817 Two derived classes that provide the actual areas functionality are:
822 To construct them, one also needs to specify how one wishes the area
823 to be calculated, via a class
830 - new clustering strategies have been added:
833 N2MinHeapTiled : like N2Tiled, except that the non-geometric
834 part has been replaced with a N ln N algorithm
835 (overall the strategy still scales as N^2, but with a
838 NlnNCam, NlnNCam2pi2R, NlnNCam4pi:
840 NlnN strategies specific to the Cambridge/Aachen
841 jet-finder -- the fastest of them is NlnNCam.
842 Depending on the size of the event and of the CPU
843 cache it may be up to 2.5 times faster than the
844 CGAL-based NlnN strategy. Experiment on your own
845 hardware and events to establish whether the
846 speed gain is significant.
848 These strategies are based on the work on dynamic
849 Closest Pair problems by Timothy Chan.
851 Best : (was present before) now attempts to select best
852 among N2Plain, N2Tiled, N2MinHeapTiled, NlnN.
854 As the best option for a given N may depend on R
855 and the event structure, you are advised to
856 experiment with individual strategies if the
857 last few tens of percent in speed are critical.
861 Updates to user interface
862 -------------------------
864 While the v1 interface to fastjet has been maintained for backwards
865 compatibility, for new developments in v2 and related forthcoming
866 work, a new interface is provided as follows:
868 - User accessible classes and enums have had the "Fj" prefix removed
869 and are instead now in namespace fastjet; the corresponding include
870 files are in the include/fastjet directory. So, for example instead
873 #include "FjClusterSequence.hh"
875 FjClusterSequence clust_seq(...)
877 one now uses the following
879 #include "fastjet/ClusterSequence.hh"
883 If typing "fastjet::" the whole time seems too
long-winded, you can
884 abbreviate "fastjet" as "fj" with
886 namespace fj = fastjet;
888 or eliminate the need for it altogether with
890 using namespace fastjet;
892 - a new class, fastjet::
JetDefinition, has been introduced for holding
893 the details of the jet finder (which one, value of R, etc...) that
894 is to be used in a given clustering.
896 #include "fastjet/JetDefinition.hh"
897 #include "fastjet/ClusterSequence.hh"
909 - some errors that previously were assertions now
throw an
910 fastjet::Error -- exception. A fully uniform handling of exceptions
911 is currently some way away however and users
for whom
this is an
912 important issue should contact the authors.