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#include <BackgroundEstimator.h>
Public Member Functions | |
| BackgroundEstimator (const ClusterSequenceAreaBase &csa, const RangeDefinition &range) | |
| double | empty_area () |
| double | mean_area () |
| get the median area of the jets used to actually compute the background properties | |
| double | median_rho () |
| get the median rho | |
| double | n_empty_jets () |
| unsigned int | n_jets_excluded () |
| unsigned int | n_jets_used () |
| get the number of jets used to actually compute the background properties | |
| void | reset () |
| double | rho () |
| synonym for median rho [[do we have this? Both?]] | |
| void | set_excluded_jets (const std::vector< PseudoJet > &excluded_jets) |
| void | set_included_jets (const std::vector< PseudoJet > &included_jets, bool all_from_inclusive=true) |
| void | set_use_area_4vector (bool use_it=true) |
| double | sigma () |
| get the sigma | |
| ~BackgroundEstimator () | |
| default dtor | |
Private Member Functions | |
| void | _compute () |
| do the actual job | |
| void | _recompute_if_needed () |
Private Attributes | |
| bool | _all_from_inclusive |
| when true, we'll assume that the incl jets are the complete set | |
| const ClusterSequenceAreaBase & | _csa |
| cluster sequence to get jets and areas from | |
| double | _empty_area |
| the empty (pure-ghost/unclustered) area! | |
| std::vector< PseudoJet > | _excluded_jets |
| jets to be excluded | |
| std::vector< PseudoJet > | _included_jets |
| jets to be used | |
| double | _mean_area |
| mean area of the jets used to estimate the background | |
| double | _median_rho |
| background estimated density per unit area | |
| double | _n_empty_jets |
| number of empty (pure-ghost) jets | |
| unsigned int | _n_jets_excluded |
| number of jets that have explicitly been excluded | |
| unsigned int | _n_jets_used |
| number of jets used to estimate the background | |
| const RangeDefinition & | _range |
| range to compute the background in | |
| double | _sigma |
| background estimated fluctuations | |
| bool | _uptodate |
| true when the background computation is up-to-date | |
| bool | _use_area_4vector |
Class to estimate the density of the background per unit area
The default behaviour of this class is to compute the global properties of the background as it is done in ClusterSequenceArea. On top of that, we provide methods to specify an explicit set of jets to use or a list of jets to exclude. We also provide all sorts of additional information regarding the background estimation like the jets that have been used or the number of pure-ghost jets.
Default behaviour: by default the list of included jets is the inclusive jets from the given ClusterSequence; the list of explicitly excluded jets is empty; we use 4-vector area
Beware: by default, to correctly handle partially empty events, the class attempts to calculate an "empty area", based (schematically) on
range.total_area() - sum_{jets_in_range} jets.area()
For ranges with small areas, this can be innacurate (particularly relevant in dense events where empty_area should be zero and ends up not being zero).
This calculation of empty area can be avoided if you supply a ClusterSequenceArea class with explicit ghosts (ActiveAreaExplicitGhosts). This is _recommended_!
Definition at line 42 of file BackgroundEstimator.h.
| BackgroundEstimator::BackgroundEstimator | ( | const ClusterSequenceAreaBase & | csa, |
| const RangeDefinition & | range | ||
| ) |
| BackgroundEstimator::~BackgroundEstimator | ( | ) |
| void BackgroundEstimator::_compute | ( | ) | [private] |
do the actual job
Definition at line 58 of file BackgroundEstimator.cc.
References _all_from_inclusive, _csa, _empty_area, _excluded_jets, _included_jets, _mean_area, _median_rho, _n_empty_jets, _n_jets_excluded, _n_jets_used, _range, _sigma, _uptodate, _use_area_4vector, error, i, j, python::multivaluedict::sort(), and mathSSE::sqrt().
Referenced by _recompute_if_needed().
{
//TODO: check that the alg is OK for median computation
//_check_jet_alg_good_for_median();
// fill the vector of pt/area with the jets
// - in included_jets
// - not in excluded_jets
// - in the range
vector<double> pt_over_areas;
double total_area = 0.0;
_n_jets_used = 0;
_n_jets_excluded = 0;
for (unsigned i = 0; i < _included_jets.size(); i++) {
const PseudoJet & current_jet = _included_jets[i];
// check that the jet is not explicitly excluded
// we'll compare them using their cluster_history_index
bool excluded = false;
int ref_idx = current_jet.cluster_hist_index();
for (unsigned int j = 0; j < _excluded_jets.size(); j++)
excluded |= (_excluded_jets[j].cluster_hist_index() == ref_idx);
// check if the jet is in the range
if (_range.is_in_range(current_jet)){
if (excluded){
// keep track of the explicitly excluded jets
_n_jets_excluded++;
} else {
double this_area = (_use_area_4vector)
? _csa.area_4vector(current_jet).perp()
: _csa.area(current_jet);
pt_over_areas.push_back(current_jet.perp()/this_area);
total_area += this_area;
_n_jets_used++;
}
}
}
// there is nothing inside our region, so answer will always be zero
if (pt_over_areas.size() == 0) {
_median_rho = 0.0;
_sigma = 0.0;
_mean_area = 0.0;
return;
}
// get median (pt/area) [this is the "old" median definition. It considers
// only the "real" jets in calculating the median, i.e. excluding the
// only-ghost ones; it will be supplemented with more info below]
sort(pt_over_areas.begin(), pt_over_areas.end());
// determine the number of empty jets
_empty_area = 0.0;
_n_empty_jets = 0.0;
if (_csa.has_explicit_ghosts()) {
_empty_area = 0.0;
_n_empty_jets = 0;
} else if (_all_from_inclusive) {
_empty_area = _csa.empty_area(_range);
_n_empty_jets = _csa.n_empty_jets(_range);
} else {
_empty_area = _csa.empty_area_from_jets(_included_jets, _range);
_mean_area = total_area / _n_jets_used; // temporary value
_n_empty_jets = _empty_area / _mean_area;
}
double total_njets = _n_jets_used + _n_empty_jets;
total_area += _empty_area;
// now get the median & error, accounting for empty jets
// define the fractions of distribution at median, median-1sigma
double posn[2] = {0.5, (1.0-0.6827)/2.0};
double res[2];
for (int i = 0; i < 2; i++) {
double nj_median_pos = (total_njets-1)*posn[i] - _n_empty_jets;
double nj_median_ratio;
if (nj_median_pos >= 0 && pt_over_areas.size() > 1) {
int int_nj_median = int(nj_median_pos);
nj_median_ratio =
pt_over_areas[int_nj_median] * (int_nj_median+1-nj_median_pos)
+ pt_over_areas[int_nj_median+1] * (nj_median_pos - int_nj_median);
} else {
nj_median_ratio = 0.0;
}
res[i] = nj_median_ratio;
}
// store the results
double error = res[0] - res[1];
_median_rho = res[0];
_mean_area = total_area / total_njets;
_sigma = error * sqrt(_mean_area);
// record that the computation has been performed
_uptodate = true;
}
| void fastjet::BackgroundEstimator::_recompute_if_needed | ( | ) | [inline, private] |
check if the properties need to be recomputed and do so if needed
Definition at line 144 of file BackgroundEstimator.h.
References _compute(), and _uptodate.
Referenced by empty_area(), mean_area(), median_rho(), n_empty_jets(), n_jets_excluded(), n_jets_used(), and sigma().
| double fastjet::BackgroundEstimator::empty_area | ( | ) | [inline] |
returns the estimate of the area (within Range) that is not occupied by the jets (excluded jets are removed from this count)
Definition at line 99 of file BackgroundEstimator.h.
References _empty_area, and _recompute_if_needed().
{
_recompute_if_needed();
return _empty_area;
}
| double fastjet::BackgroundEstimator::mean_area | ( | ) | [inline] |
get the median area of the jets used to actually compute the background properties
Definition at line 71 of file BackgroundEstimator.h.
References _mean_area, and _recompute_if_needed().
{
_recompute_if_needed();
return _mean_area;
}
| double fastjet::BackgroundEstimator::median_rho | ( | ) | [inline] |
get the median rho
Definition at line 56 of file BackgroundEstimator.h.
References _median_rho, and _recompute_if_needed().
Referenced by rho().
{
_recompute_if_needed();
return _median_rho;
}
| double fastjet::BackgroundEstimator::n_empty_jets | ( | ) | [inline] |
get the number of empty jets used when computing the background properties; (it is deduced from the empty area with an assumption about the average area of jets)
Definition at line 92 of file BackgroundEstimator.h.
References _n_empty_jets, and _recompute_if_needed().
{
_recompute_if_needed();
return _n_empty_jets;
}
| unsigned int fastjet::BackgroundEstimator::n_jets_excluded | ( | ) | [inline] |
get the number of jets (within the given range) that have been explicitly excluded when computing the background properties
Definition at line 84 of file BackgroundEstimator.h.
References _n_jets_excluded, and _recompute_if_needed().
{
_recompute_if_needed();
return _n_jets_excluded;
}
| unsigned int fastjet::BackgroundEstimator::n_jets_used | ( | ) | [inline] |
get the number of jets used to actually compute the background properties
Definition at line 77 of file BackgroundEstimator.h.
References _n_jets_used, and _recompute_if_needed().
{
_recompute_if_needed();
return _n_jets_used;
}
| void BackgroundEstimator::reset | ( | void | ) |
reset to default values set the list of included jets to the inclusive jets and clear the excluded ones
Definition at line 36 of file BackgroundEstimator.cc.
References _all_from_inclusive, _csa, _empty_area, _excluded_jets, _included_jets, _mean_area, _median_rho, _n_empty_jets, _n_jets_excluded, _n_jets_used, _sigma, _uptodate, and set_use_area_4vector().
Referenced by BackgroundEstimator().
{
// set the list of included jets to the inclusive jets
_included_jets = _csa.inclusive_jets();
_all_from_inclusive = true;
//set_included_jets(_csa.inclusive_jets());
// clear the list of explicitly excluded jets
_excluded_jets.clear();
//set_excluded_jets(vector<PseudoJet>());
// set the remaining default parameters
set_use_area_4vector(); // true by default
// reset the computed values
_median_rho = _sigma = _mean_area = 0.0;
_n_jets_used = _n_jets_excluded = _n_empty_jets = 0;
_empty_area = 0.0;
_uptodate = false;
}
| double fastjet::BackgroundEstimator::rho | ( | ) | [inline] |
synonym for median rho [[do we have this? Both?]]
Definition at line 62 of file BackgroundEstimator.h.
References median_rho().
Referenced by VirtualJetProducer::writeJets().
{return median_rho();}
| void fastjet::BackgroundEstimator::set_excluded_jets | ( | const std::vector< PseudoJet > & | excluded_jets | ) | [inline] |
set the list of explicitly excluded jets
| excluded_jets | the list of jets that have to be explicitly excluded |
Definition at line 133 of file BackgroundEstimator.h.
References _excluded_jets, and _uptodate.
Referenced by VirtualJetProducer::writeJets().
{
_excluded_jets = excluded_jets;
_uptodate = false;
}
| void fastjet::BackgroundEstimator::set_included_jets | ( | const std::vector< PseudoJet > & | included_jets, |
| bool | all_from_inclusive = true |
||
| ) | [inline] |
set the list of included jets
| included_jets | the list of jets to include |
| all_from_included | when true, we'll assume that the cluster sequence inclusive jets give all the potential jets in the range. In practice this means that the empty area will be computed from the inclusive jets rather than from the 'included_jets'. You can overwrite the default value and send it to 'false' e.g. when the included_jets you provide are themselves a list of inclusive jets. |
Definition at line 125 of file BackgroundEstimator.h.
References _all_from_inclusive, _included_jets, and _uptodate.
{
_included_jets = included_jets;
_all_from_inclusive = all_from_inclusive;
_uptodate = false;
}
| void fastjet::BackgroundEstimator::set_use_area_4vector | ( | bool | use_it = true | ) | [inline] |
specify if one uses the scalar or 4-vector area
| use_it | whether one uses the 4-vector area or not (true by default) |
Definition at line 113 of file BackgroundEstimator.h.
References _use_area_4vector.
Referenced by reset().
{
_use_area_4vector = use_it;
}
| double fastjet::BackgroundEstimator::sigma | ( | ) | [inline] |
get the sigma
Definition at line 65 of file BackgroundEstimator.h.
References _recompute_if_needed(), and _sigma.
Referenced by VirtualJetProducer::writeJets().
{
_recompute_if_needed();
return _sigma;
}
bool fastjet::BackgroundEstimator::_all_from_inclusive [private] |
when true, we'll assume that the incl jets are the complete set
Definition at line 155 of file BackgroundEstimator.h.
Referenced by _compute(), reset(), and set_included_jets().
const ClusterSequenceAreaBase& fastjet::BackgroundEstimator::_csa [private] |
cluster sequence to get jets and areas from
Definition at line 151 of file BackgroundEstimator.h.
Referenced by _compute(), and reset().
double fastjet::BackgroundEstimator::_empty_area [private] |
the empty (pure-ghost/unclustered) area!
Definition at line 165 of file BackgroundEstimator.h.
Referenced by _compute(), empty_area(), and reset().
std::vector<PseudoJet> fastjet::BackgroundEstimator::_excluded_jets [private] |
jets to be excluded
Definition at line 154 of file BackgroundEstimator.h.
Referenced by _compute(), reset(), and set_excluded_jets().
std::vector<PseudoJet> fastjet::BackgroundEstimator::_included_jets [private] |
jets to be used
Definition at line 153 of file BackgroundEstimator.h.
Referenced by _compute(), reset(), and set_included_jets().
double fastjet::BackgroundEstimator::_mean_area [private] |
mean area of the jets used to estimate the background
Definition at line 161 of file BackgroundEstimator.h.
Referenced by _compute(), mean_area(), and reset().
double fastjet::BackgroundEstimator::_median_rho [private] |
background estimated density per unit area
Definition at line 159 of file BackgroundEstimator.h.
Referenced by _compute(), median_rho(), and reset().
double fastjet::BackgroundEstimator::_n_empty_jets [private] |
number of empty (pure-ghost) jets
Definition at line 164 of file BackgroundEstimator.h.
Referenced by _compute(), n_empty_jets(), and reset().
unsigned int fastjet::BackgroundEstimator::_n_jets_excluded [private] |
number of jets that have explicitly been excluded
Definition at line 163 of file BackgroundEstimator.h.
Referenced by _compute(), n_jets_excluded(), and reset().
unsigned int fastjet::BackgroundEstimator::_n_jets_used [private] |
number of jets used to estimate the background
Definition at line 162 of file BackgroundEstimator.h.
Referenced by _compute(), n_jets_used(), and reset().
const RangeDefinition& fastjet::BackgroundEstimator::_range [private] |
range to compute the background in
Definition at line 152 of file BackgroundEstimator.h.
Referenced by _compute().
double fastjet::BackgroundEstimator::_sigma [private] |
background estimated fluctuations
Definition at line 160 of file BackgroundEstimator.h.
Referenced by _compute(), reset(), and sigma().
bool fastjet::BackgroundEstimator::_uptodate [private] |
true when the background computation is up-to-date
Definition at line 168 of file BackgroundEstimator.h.
Referenced by _compute(), _recompute_if_needed(), reset(), set_excluded_jets(), and set_included_jets().
bool fastjet::BackgroundEstimator::_use_area_4vector [private] |
Definition at line 156 of file BackgroundEstimator.h.
Referenced by _compute(), and set_use_area_4vector().
1.7.3