base class that sets interface for extensions of ClusterSequence that provide information about the area of each jet More...
#include <ClusterSequenceAreaBase.hh>
Public Member Functions | |
| template<class L > | |
| ClusterSequenceAreaBase (const std::vector< L > &pseudojets, const JetDefinition &jet_def, const bool &writeout_combinations=false) | |
| a constructor which just carries out the construction of the parent class | |
| ClusterSequenceAreaBase () | |
| default constructor | |
| virtual | ~ClusterSequenceAreaBase () |
| destructor | |
| virtual double | area (const PseudoJet &) const |
| return the area associated with the given jet; this base class returns 0. | |
| virtual double | area_error (const PseudoJet &) const |
| return the error (uncertainty) associated with the determination of the area of this jet; this base class returns 0. | |
| virtual PseudoJet | area_4vector (const PseudoJet &) const |
| return a PseudoJet whose 4-vector is defined by the following integral | |
| virtual bool | is_pure_ghost (const PseudoJet &) const |
| true if a jet is made exclusively of ghosts | |
| virtual bool | has_explicit_ghosts () const |
| returns true if ghosts are explicitly included within jets for this ClusterSequence; | |
| virtual double | empty_area (const RangeDefinition &range) const |
| return the total area, within range, that is free of jets, in general based on the inclusive jets | |
| double | empty_area_from_jets (const std::vector< PseudoJet > &all_jets, const RangeDefinition &range) const |
| return the total area, within range, that is free of jets, based on the supplied all_jets | |
| virtual double | n_empty_jets (const RangeDefinition &range) const |
| return something similar to the number of pure ghost jets in the given range in an active area case. | |
| double | median_pt_per_unit_area (const RangeDefinition &range) const |
| the median of (pt/area) for jets contained within range, making use also of the info on n_empty_jets | |
| double | median_pt_per_unit_area_4vector (const RangeDefinition &range) const |
| the median of (pt/area_4vector) for jets contained within making use also of the info on n_empty_jets | |
| double | median_pt_per_unit_something (const RangeDefinition &range, bool use_area_4vector) const |
the function that does the work for median_pt_per_unit_area and median_pt_per_unit_area_4vector:
| |
| virtual void | get_median_rho_and_sigma (const RangeDefinition &range, bool use_area_4vector, double &median, double &sigma, double &mean_area) const |
| using jets withing range (and with 4-vector areas if use_area_4vector), calculate the median pt/area, as well as an "error" (uncertainty), which is defined as the 1-sigma half-width of the distribution of pt/A, obtained by looking for the point below which we have (1-0.6827)/2 of the jets (including empty jets). | |
| virtual void | get_median_rho_and_sigma (const std::vector< PseudoJet > &all_jets, const RangeDefinition &range, bool use_area_4vector, double &median, double &sigma, double &mean_area, bool all_are_inclusive=false) const |
| a more advanced version of get_median_rho_and_sigma, which allows one to use any "view" of the event containing all jets (so that, e.g. | |
| virtual void | get_median_rho_and_sigma (const RangeDefinition &range, bool use_area_4vector, double &median, double &sigma) const |
| same as the full version of get_median_rho_and_error, but without access to the mean_area | |
| virtual void | parabolic_pt_per_unit_area (double &a, double &b, const RangeDefinition &range, double exclude_above=-1.0, bool use_area_4vector=false) const |
| fits a form pt_per_unit_area(y) = a + b*y^2 in the range "range". | |
| std::vector< PseudoJet > | subtracted_jets (const double rho, const double ptmin=0.0) const |
| return a vector of all subtracted jets, using area_4vector, given rho. | |
| std::vector< PseudoJet > | subtracted_jets (const RangeDefinition &range, const double ptmin=0.0) const |
| return a vector of subtracted jets, using area_4vector. | |
| PseudoJet | subtracted_jet (const PseudoJet &jet, const double rho) const |
| return a subtracted jet, using area_4vector, given rho | |
| PseudoJet | subtracted_jet (const PseudoJet &jet, const RangeDefinition &range) const |
| return a subtracted jet, using area_4vector; note that this is potentially inefficient if repeatedly used for many different jets, because rho will be recalculated each time around. | |
| double | subtracted_pt (const PseudoJet &jet, const double rho, bool use_area_4vector=false) const |
| return the subtracted pt, given rho | |
| double | subtracted_pt (const PseudoJet &jet, const RangeDefinition &range, bool use_area_4vector=false) const |
| return the subtracted pt; note that this is potentially inefficient if repeatedly used for many different jets, because rho will be recalculated each time around. | |
Detailed Description
base class that sets interface for extensions of ClusterSequence that provide information about the area of each jet
the virtual functions here all return 0, since no area determination is implemented.
Definition at line 47 of file ClusterSequenceAreaBase.hh.
Member Function Documentation
| virtual double fastjet::ClusterSequenceAreaBase::area | ( | const PseudoJet & | ) | const [inline, virtual] |
return the area associated with the given jet; this base class returns 0.
Reimplemented in fastjet::ClusterSequenceActiveArea, fastjet::ClusterSequenceActiveAreaExplicitGhosts, fastjet::ClusterSequenceArea, and fastjet::ClusterSequenceVoronoiArea.
Definition at line 69 of file ClusterSequenceAreaBase.hh.
Referenced by fastjet::ClusterSequenceStructure::area(), empty_area_from_jets(), parabolic_pt_per_unit_area(), and subtracted_pt().
{return 0.0;}
| virtual double fastjet::ClusterSequenceAreaBase::area_error | ( | const PseudoJet & | ) | const [inline, virtual] |
return the error (uncertainty) associated with the determination of the area of this jet; this base class returns 0.
Reimplemented in fastjet::ClusterSequenceActiveArea, fastjet::ClusterSequenceArea, and fastjet::ClusterSequenceVoronoiArea.
Definition at line 73 of file ClusterSequenceAreaBase.hh.
Referenced by fastjet::ClusterSequenceStructure::area_error().
{return 0.0;}
| virtual PseudoJet fastjet::ClusterSequenceAreaBase::area_4vector | ( | const PseudoJet & | ) | const [inline, virtual] |
return a PseudoJet whose 4-vector is defined by the following integral
drap d PseudoJet("rap,phi,pt=one") * Theta("rap,phi inside jet boundary")
where PseudoJet("rap,phi,pt=one") is a 4-vector with the given rapidity (rap), azimuth (phi) and pt=1, while Theta("rap,phi inside jet boundary") is a function that is 1 when rap,phi define a direction inside the jet boundary and 0 otherwise.
This base class returns a null 4-vector.
Reimplemented in fastjet::ClusterSequenceActiveArea, fastjet::ClusterSequenceActiveAreaExplicitGhosts, fastjet::ClusterSequenceArea, and fastjet::ClusterSequenceVoronoiArea.
Definition at line 86 of file ClusterSequenceAreaBase.hh.
Referenced by fastjet::ClusterSequenceStructure::area_4vector(), parabolic_pt_per_unit_area(), and subtracted_jet().
{
return PseudoJet(0.0,0.0,0.0,0.0);}
| virtual bool fastjet::ClusterSequenceAreaBase::is_pure_ghost | ( | const PseudoJet & | ) | const [inline, virtual] |
true if a jet is made exclusively of ghosts
NB: most area classes do not give any explicit ghost jets, but some do, and they should replace this function with their own version.
Reimplemented in fastjet::ClusterSequenceActiveAreaExplicitGhosts, and fastjet::ClusterSequenceArea.
Definition at line 94 of file ClusterSequenceAreaBase.hh.
Referenced by fastjet::ClusterSequenceStructure::is_pure_ghost().
{
return false;
}
| virtual bool fastjet::ClusterSequenceAreaBase::has_explicit_ghosts | ( | ) | const [inline, virtual] |
returns true if ghosts are explicitly included within jets for this ClusterSequence;
Derived classes that do include explicit ghosts should provide an alternative version of this routine and set it properly.
Reimplemented in fastjet::ClusterSequenceActiveAreaExplicitGhosts, and fastjet::ClusterSequenceArea.
Definition at line 103 of file ClusterSequenceAreaBase.hh.
Referenced by fastjet::BackgroundEstimator::BackgroundEstimator(), and empty_area().
{
return false;
}
| double fastjet::ClusterSequenceAreaBase::empty_area | ( | const RangeDefinition & | range | ) | const [virtual] |
return the total area, within range, that is free of jets, in general based on the inclusive jets
return the total area, within range, that is free of jets.
Calculate this as (range area) - {i in range} A_i
for ClusterSequences with explicit ghosts, assume that there will never be any empty area, i.e. it is always filled in by pure ghosts jets. This holds for seq.rec. algorithms
Reimplemented in fastjet::ClusterSequenceActiveArea, fastjet::ClusterSequenceActiveAreaExplicitGhosts, fastjet::ClusterSequenceArea, and fastjet::ClusterSequencePassiveArea.
Definition at line 55 of file ClusterSequenceAreaBase.cc.
References empty_area_from_jets(), has_explicit_ghosts(), and fastjet::ClusterSequence::inclusive_jets().
{
if (has_explicit_ghosts()) {return 0.0;}
else { return empty_area_from_jets(inclusive_jets(0.0), range);}
}
| double fastjet::ClusterSequenceAreaBase::empty_area_from_jets | ( | const std::vector< PseudoJet > & | all_jets, | |
| const RangeDefinition & | range | |||
| ) | const |
return the total area, within range, that is free of jets, based on the supplied all_jets
return the total area, within range, that is free of jets.
Calculate this as (range area) - {i in range} A_i
Definition at line 67 of file ClusterSequenceAreaBase.cc.
References area(), fastjet::RangeDefinition::area(), and fastjet::RangeDefinition::is_in_range().
Referenced by empty_area().
{
double empty = range.area();
for (unsigned i = 0; i < all_jets.size(); i++) {
if (range.is_in_range(all_jets[i])) empty -= area(all_jets[i]);
}
return empty;
}
| virtual double fastjet::ClusterSequenceAreaBase::n_empty_jets | ( | const RangeDefinition & | range | ) | const [inline, virtual] |
return something similar to the number of pure ghost jets in the given range in an active area case.
For the local implementation we return empty_area/(0.55 pi R^2), based on measured properties of ghost jets with kt and cam. Note that the number returned is a double.
Reimplemented in fastjet::ClusterSequence1GhostPassiveArea, fastjet::ClusterSequenceActiveArea, and fastjet::ClusterSequenceArea.
Definition at line 121 of file ClusterSequenceAreaBase.hh.
{
double R = jet_def().R();
return empty_area(range)/(0.55*pi*R*R);
}
| double fastjet::ClusterSequenceAreaBase::median_pt_per_unit_something | ( | const RangeDefinition & | range, | |
| bool | use_area_4vector | |||
| ) | const |
the function that does the work for median_pt_per_unit_area and median_pt_per_unit_area_4vector:
- something_is_area_4vect = false -> use plain area
- something_is_area_4vect = true -> use 4-vector area
the median of (pt/area) for jets contained within range, counting the empty area as if it were made up of a collection of empty jets each of area (0.55 * pi R^2).
Definition at line 91 of file ClusterSequenceAreaBase.cc.
References get_median_rho_and_sigma().
Referenced by median_pt_per_unit_area(), and median_pt_per_unit_area_4vector().
{
double median, sigma, mean_area;
get_median_rho_and_sigma(range, use_area_4vector, median, sigma, mean_area);
return median;
}
| void fastjet::ClusterSequenceAreaBase::get_median_rho_and_sigma | ( | const RangeDefinition & | range, | |
| bool | use_area_4vector, | |||
| double & | median, | |||
| double & | sigma, | |||
| double & | mean_area | |||
| ) | const [virtual] |
using jets withing range (and with 4-vector areas if use_area_4vector), calculate the median pt/area, as well as an "error" (uncertainty), which is defined as the 1-sigma half-width of the distribution of pt/A, obtained by looking for the point below which we have (1-0.6827)/2 of the jets (including empty jets).
The subtraction for a jet with uncorrected pt pt^U and area A is
pt^S = pt^U - median*A +- sigma*sqrt(A)
where the error is only that associated with the fluctuations in the noise and not that associated with the noise having caused changes in the hard-particle content of the jet.
NB: subtraction may also be done with 4-vector area of course, and this is recommended for jets with larger values of R, as long as rho has also been determined with a 4-vector area; using a scalar area causes one to neglect terms of relative order $R^2/8$ in the jet $p_t$.
Reimplemented in fastjet::ClusterSequenceArea.
Definition at line 157 of file ClusterSequenceAreaBase.cc.
References fastjet::ClusterSequence::inclusive_jets().
Referenced by median_pt_per_unit_something().
{
vector<PseudoJet> incl_jets = inclusive_jets();
get_median_rho_and_sigma(incl_jets, range, use_area_4vector,
median, sigma, mean_area, true);
}
| virtual void fastjet::ClusterSequenceAreaBase::get_median_rho_and_sigma | ( | const std::vector< PseudoJet > & | all_jets, | |
| const RangeDefinition & | range, | |||
| bool | use_area_4vector, | |||
| double & | median, | |||
| double & | sigma, | |||
| double & | mean_area, | |||
| bool | all_are_inclusive = false | |||
| ) | const [virtual] |
a more advanced version of get_median_rho_and_sigma, which allows one to use any "view" of the event containing all jets (so that, e.g.
one might use Cam on a different resolution scale without have to rerun the algorithm).
By default it will assume that "all" are not inclusive jets, so that in dealing with empty area it has to calculate the number of empty jets based on the empty area and the the observed <area> of jets rather than a surmised area
Note that for small effective radii, this can cause problems because the harder jets get an area >> <ghost-jet-area> and so the estimate comes out all wrong. In these situations it is highly advisable to use an area with explicit ghosts, since then the "empty" jets are actually visible.
Reimplemented in fastjet::ClusterSequenceArea.
| void fastjet::ClusterSequenceAreaBase::parabolic_pt_per_unit_area | ( | double & | a, | |
| double & | b, | |||
| const RangeDefinition & | range, | |||
| double | exclude_above = -1.0, |
|||
| bool | use_area_4vector = false | |||
| ) | const [virtual] |
fits a form pt_per_unit_area(y) = a + b*y^2 in the range "range".
fits a form pt_per_unit_area(y) = a + b*y^2 for jets in range.
exclude_above allows one to exclude large values of pt/area from fit. (if negative, the cut is discarded) use_area_4vector = true uses the 4vector areas.
exclude_above allows one to exclude large values of pt/area from fit. use_area_4vector = true uses the 4vector areas.
Reimplemented in fastjet::ClusterSequenceArea.
Definition at line 105 of file ClusterSequenceAreaBase.cc.
References area(), area_4vector(), fastjet::ClusterSequence::inclusive_jets(), fastjet::RangeDefinition::is_in_range(), and fastjet::PseudoJet::perp().
{
int n=0;
int n_excluded = 0;
double mean_f=0, mean_x2=0, mean_x4=0, mean_fx2=0;
vector<PseudoJet> incl_jets = inclusive_jets();
for (unsigned i = 0; i < incl_jets.size(); i++) {
if (range.is_in_range(incl_jets[i])) {
double this_area;
if ( use_area_4vector ) {
this_area = area_4vector(incl_jets[i]).perp();
} else {
this_area = area(incl_jets[i]);
}
double f = incl_jets[i].perp()/this_area;
if (exclude_above <= 0.0 || f < exclude_above) {
double x = incl_jets[i].rap(); double x2 = x*x;
mean_f += f;
mean_x2 += x2;
mean_x4 += x2*x2;
mean_fx2 += f*x2;
n++;
} else {
n_excluded++;
}
}
}
if (n <= 1) {
// meaningful results require at least two jets inside the
// area -- mind you if there are empty jets we should be in
// any case doing something special...
a = 0.0;
b = 0.0;
} else {
mean_f /= n;
mean_x2 /= n;
mean_x4 /= n;
mean_fx2 /= n;
b = (mean_f*mean_x2 - mean_fx2)/(mean_x2*mean_x2 - mean_x4);
a = mean_f - b*mean_x2;
}
//cerr << "n_excluded = "<< n_excluded << endl;
}
| vector< PseudoJet > fastjet::ClusterSequenceAreaBase::subtracted_jets | ( | const double | rho, | |
| const double | ptmin = 0.0 | |||
| ) | const |
return a vector of all subtracted jets, using area_4vector, given rho.
Only inclusive_jets above ptmin are subtracted and returned. the ordering is the same as that of sorted_by_pt(cs.inclusive_jets()), i.e. not necessarily ordered in pt once subtracted
Definition at line 268 of file ClusterSequenceAreaBase.cc.
References fastjet::ClusterSequence::inclusive_jets(), fastjet::ClusterSequence::jets(), fastjet::sorted_by_pt(), and subtracted_jet().
Referenced by subtracted_jets().
{
vector<PseudoJet> sub_jets;
vector<PseudoJet> jets = sorted_by_pt(inclusive_jets(ptmin));
for (unsigned i=0; i<jets.size(); i++) {
PseudoJet sub_jet = subtracted_jet(jets[i],rho);
sub_jets.push_back(sub_jet);
}
return sub_jets;
}
| vector< PseudoJet > fastjet::ClusterSequenceAreaBase::subtracted_jets | ( | const RangeDefinition & | range, | |
| const double | ptmin = 0.0 | |||
| ) | const |
return a vector of subtracted jets, using area_4vector.
Only inclusive_jets above ptmin are subtracted and returned. the ordering is the same as that of sorted_by_pt(cs.inclusive_jets()), i.e. not necessarily ordered in pt once subtracted
Definition at line 284 of file ClusterSequenceAreaBase.cc.
References median_pt_per_unit_area_4vector(), and subtracted_jets().
{
double rho = median_pt_per_unit_area_4vector(range);
return subtracted_jets(rho,ptmin);
}
| PseudoJet fastjet::ClusterSequenceAreaBase::subtracted_jet | ( | const PseudoJet & | jet, | |
| const RangeDefinition & | range | |||
| ) | const |
return a subtracted jet, using area_4vector; note that this is potentially inefficient if repeatedly used for many different jets, because rho will be recalculated each time around.
Definition at line 315 of file ClusterSequenceAreaBase.cc.
References median_pt_per_unit_area_4vector(), and subtracted_jet().
{
double rho = median_pt_per_unit_area_4vector(range);
PseudoJet sub_jet = subtracted_jet(jet, rho);
return sub_jet;
}
| double fastjet::ClusterSequenceAreaBase::subtracted_pt | ( | const PseudoJet & | jet, | |
| const RangeDefinition & | range, | |||
| bool | use_area_4vector = false | |||
| ) | const |
return the subtracted pt; note that this is potentially inefficient if repeatedly used for many different jets, because rho will be recalculated each time around.
Definition at line 339 of file ClusterSequenceAreaBase.cc.
References median_pt_per_unit_area(), fastjet::PseudoJet::perp(), subtracted_jet(), and subtracted_pt().
{
if ( use_area_4vector ) {
PseudoJet sub_jet = subtracted_jet(jet,range);
return sub_jet.perp();
} else {
double rho = median_pt_per_unit_area(range);
return subtracted_pt(jet,rho,false);
}
}
The documentation for this class was generated from the following files:
- include/fastjet/ClusterSequenceAreaBase.hh
- src/ClusterSequenceAreaBase.cc
