From bad4c484397bb1ec09f341d866fda9ca1d177405 Mon Sep 17 00:00:00 2001
From: Julien <julien.doerner@rub.de>
Date: Fri, 17 Nov 2023 12:49:45 +0200
Subject: [PATCH] introduce real time into candidate

---
 include/crpropa/Candidate.h |  7 +++++++
 src/Candidate.cpp           | 20 +++++++++++++++++---
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/include/crpropa/Candidate.h b/include/crpropa/Candidate.h
index 1ddb995b6..14bcac0a6 100644
--- a/include/crpropa/Candidate.h
+++ b/include/crpropa/Candidate.h
@@ -44,6 +44,7 @@ class Candidate: public Referenced {
 	double weight; /**< Weight of the candidate */
 	double redshift; /**< Current simulation time-point in terms of redshift z */
 	double trajectoryLength; /**< Comoving distance [m] the candidate has traveled so far */
+	double time; /**< Current simulation time in [s] */
 	double currentStep; /**< Size of the currently performed step in [m] comoving units */
 	double nextStep; /**< Proposed size of the next propagation step in [m] comoving units */
 
@@ -72,6 +73,12 @@ class Candidate: public Referenced {
 	void setTrajectoryLength(double length);
 	double getTrajectoryLength() const;
 
+	/**
+	 Set the total time.
+	*/
+	void setTime(double time);
+	double getTime() const;
+
 	void setRedshift(double z);
 	double getRedshift() const;
 
diff --git a/src/Candidate.cpp b/src/Candidate.cpp
index d9a6c6d20..be4527223 100644
--- a/src/Candidate.cpp
+++ b/src/Candidate.cpp
@@ -7,7 +7,7 @@
 namespace crpropa {
 
 Candidate::Candidate(int id, double E, Vector3d pos, Vector3d dir, double z, double weight) :
-		redshift(z), trajectoryLength(0), weight(1), currentStep(0), nextStep(0), active(true), parent(0) {
+		redshift(z), trajectoryLength(0), weight(1), currentStep(0), nextStep(0), active(true), parent(0), time(0) {
 	ParticleState state(id, E, pos, dir);
 	source = state;
 	created = state;
@@ -27,7 +27,7 @@ Candidate::Candidate(int id, double E, Vector3d pos, Vector3d dir, double z, dou
 }
 
 Candidate::Candidate(const ParticleState &state) :
-		source(state), created(state), current(state), previous(state), redshift(0), trajectoryLength(0), currentStep(0), nextStep(0), active(true), parent(0) {
+		source(state), created(state), current(state), previous(state), redshift(0), trajectoryLength(0), currentStep(0), nextStep(0), active(true), parent(0), time(0) {
 
 #if defined(OPENMP_3_1)
 		#pragma omp atomic capture
@@ -57,6 +57,10 @@ double Candidate::getTrajectoryLength() const {
 	return trajectoryLength;
 }
 
+double Candidate::getTime() const {
+	return time;
+}
+
 double Candidate::getWeight() const {
 	return weight;
 }
@@ -77,6 +81,10 @@ void Candidate::setTrajectoryLength(double a) {
 	trajectoryLength = a;
 }
 
+void Candidate::setTime(double t) {
+	time = t;
+}
+
 void Candidate::setWeight(double w) {
 	weight = w;
 }
@@ -84,6 +92,7 @@ void Candidate::setWeight(double w) {
 void Candidate::setCurrentStep(double lstep) {
 	currentStep = lstep;
 	trajectoryLength += lstep;
+	time += lstep / c_light; // adjust for v < c
 }
 
 void Candidate::setNextStep(double step) {
@@ -128,6 +137,7 @@ void Candidate::addSecondary(int id, double energy, double weight) {
 	ref_ptr<Candidate> secondary = new Candidate;
 	secondary->setRedshift(redshift);
 	secondary->setTrajectoryLength(trajectoryLength);
+	secondary->setTime(time);
 	secondary->setWeight(weight);
 	secondary->source = source;
 	secondary->previous = previous;
@@ -142,7 +152,9 @@ void Candidate::addSecondary(int id, double energy, double weight) {
 void Candidate::addSecondary(int id, double energy, Vector3d position, double weight) {
 	ref_ptr<Candidate> secondary = new Candidate;
 	secondary->setRedshift(redshift);
-	secondary->setTrajectoryLength(trajectoryLength - (current.getPosition() - position).getR() );
+	double dR = (current.getPosition() - position).getR();
+	secondary->setTrajectoryLength(trajectoryLength - dR);
+	secondary->setTime(time - dR / c_light); // adjust for v < c
 	secondary->setWeight(weight);
 	secondary->source = source;
 	secondary->previous = previous;
@@ -180,6 +192,7 @@ ref_ptr<Candidate> Candidate::clone(bool recursive) const {
 	cloned->redshift = redshift;
 	cloned->weight = weight;
 	cloned->trajectoryLength = trajectoryLength;
+	cloned->time = time;
 	cloned->currentStep = currentStep;
 	cloned->nextStep = nextStep;
 	if (recursive) {
@@ -228,6 +241,7 @@ uint64_t Candidate::nextSerialNumber = 0;
 void Candidate::restart() {
 	setActive(true);
 	setTrajectoryLength(0);
+	setTime(0);
 	previous = source;
 	current = source;
 }