From ab33c557e292e40946ce9a683d6d26f30e329be7 Mon Sep 17 00:00:00 2001
From: Dave Casper <dcasper@uci.edu>
Date: Thu, 1 Mar 2018 22:40:17 -0800
Subject: [PATCH] Add logic to compute and return first and second derivatives
of density function.
Former-commit-id: 6f0360ba4058e820297bf50d7ce89604f9b408e2
---
.../IVertexTrackDensityEstimator.h | 7 ++++++-
.../GaussianTrackDensity.h | 7 ++++++-
.../src/GaussianTrackDensity.cxx | 20 +++++++++++++++++--
3 files changed, 30 insertions(+), 4 deletions(-)
diff --git a/Tracking/TrkVertexFitter/TrkVertexFitterInterfaces/TrkVertexFitterInterfaces/IVertexTrackDensityEstimator.h b/Tracking/TrkVertexFitter/TrkVertexFitterInterfaces/TrkVertexFitterInterfaces/IVertexTrackDensityEstimator.h
index 01c1bb1a39c..f6d60e480cb 100755
--- a/Tracking/TrkVertexFitter/TrkVertexFitterInterfaces/TrkVertexFitterInterfaces/IVertexTrackDensityEstimator.h
+++ b/Tracking/TrkVertexFitter/TrkVertexFitterInterfaces/TrkVertexFitterInterfaces/IVertexTrackDensityEstimator.h
@@ -70,7 +70,12 @@ namespace Trk
/**
* Evaluate the density function at the specified coordinate along the beam-line.
*/
- virtual double trackDensity(double z) = 0;
+ virtual double trackDensity(double z) const = 0;
+
+ /*
+ * Evaluate the density function and its first two derivatives at the specified coordinate.
+ */
+ virtual void trackDensity(double z, double& density, double& firstDerivative, double& secondDerivative) const = 0;
/**
* Resets the internal state of the tool, forgetting all tracks previously added.
diff --git a/Tracking/TrkVertexFitter/TrkVertexSeedFinderUtils/TrkVertexSeedFinderUtils/GaussianTrackDensity.h b/Tracking/TrkVertexFitter/TrkVertexSeedFinderUtils/TrkVertexSeedFinderUtils/GaussianTrackDensity.h
index fe708753e7e..ca56a88be79 100644
--- a/Tracking/TrkVertexFitter/TrkVertexSeedFinderUtils/TrkVertexSeedFinderUtils/GaussianTrackDensity.h
+++ b/Tracking/TrkVertexFitter/TrkVertexSeedFinderUtils/TrkVertexSeedFinderUtils/GaussianTrackDensity.h
@@ -64,7 +64,12 @@ namespace Trk
/**
* Evaluate the density function at the specified coordinate along the beam-line.
*/
- virtual double trackDensity(double z);
+ virtual double trackDensity(double z) const;
+
+ /**
+ * Evaluate the density and its first two derivatives at the specified coordinate.
+ */
+ virtual void trackDensity(double z, double& density, double& firstDerivative, double& secondDerivativec) const;
/**
* Resets the internal state of the tool, forgetting all tracks previously added.
diff --git a/Tracking/TrkVertexFitter/TrkVertexSeedFinderUtils/src/GaussianTrackDensity.cxx b/Tracking/TrkVertexFitter/TrkVertexSeedFinderUtils/src/GaussianTrackDensity.cxx
index 64e202806da..06dc9822f0e 100644
--- a/Tracking/TrkVertexFitter/TrkVertexSeedFinderUtils/src/GaussianTrackDensity.cxx
+++ b/Tracking/TrkVertexFitter/TrkVertexSeedFinderUtils/src/GaussianTrackDensity.cxx
@@ -28,16 +28,32 @@ namespace Trk
return StatusCode::SUCCESS;
}
- double GaussianTrackDensity::trackDensity(double z)
+ double GaussianTrackDensity::trackDensity(double z) const
{
double sum = 0.0;
for (auto& entry : m_trackMap)
{
- sum += entry.second.constant * exp(z*entry.second.c_1 + z*z*entry.second.c_2);
+ sum += entry.second.constant * exp(z*(entry.second.c_1 + z*entry.second.c_2));
}
return sum;
}
+ void GaussianTrackDensity::trackDensity(double z, double& density, double& firstDerivative, double& secondDerivative) const
+ {
+ density = 0.0;
+ firstDerivative = 0.0;
+ secondDerivative = 0.0;
+ for (auto& entry : m_trackMap)
+ {
+ double delta = entry.second.constant * exp(z*(entry.second.c_1 + z*entry.second.c_2));
+ density += delta;
+ double qPrime = entry.second.c_1 + 2*z*entry.second.c_2;
+ double deltaPrime = delta * qPrime;
+ firstDerivative += deltaPrime;
+ secondDerivative += 2*entry.second.c_2*delta + qPrime*deltaPrime;
+ }
+ }
+
void GaussianTrackDensity::addTracks(const std::vector<const Trk::Track*>& vectorTrk)
{
std::vector<const TrackParameters*> perigeeList;
--
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