From 4748d28f3d422a0d61118ca8c9367928bf6ae4f0 Mon Sep 17 00:00:00 2001
From: "armindamon.riess" <armindamon.riess@uzh.ch>
Date: Wed, 7 Dec 2022 10:34:36 +0100
Subject: [PATCH] prepare implementation of time step
---
lib/nBodySim.cpp | 1 -
lib/tree.hpp | 4 ++--
main.cpp | 36 +++++++++++++++++++++---------------
3 files changed, 23 insertions(+), 18 deletions(-)
diff --git a/lib/nBodySim.cpp b/lib/nBodySim.cpp
index a92c3f1..7ed7323 100644
--- a/lib/nBodySim.cpp
+++ b/lib/nBodySim.cpp
@@ -62,7 +62,6 @@ nBodySim::~nBodySim() {
void nBodySim::runSimulation(double dt, unsigned nSteps) {
for (unsigned i=0; i < nSteps; ++i) {
- calculateForces();
doTimeStep(dt);
}
}
diff --git a/lib/tree.hpp b/lib/tree.hpp
index 9578237..38cca7a 100644
--- a/lib/tree.hpp
+++ b/lib/tree.hpp
@@ -12,9 +12,9 @@ public:
~Tree();
// update tree: visit each node, check if it needs to be split or merged (for example if a particle has left the region)
void update();
- // drift tree: visit each node, update center of mass and center of mass velocity
+ // drift tree: visit each node, update positions
void drift(double dt);
- // kick tree: visit each node, update center of mass velocity
+ // kick tree: visit each node, update velocities
void kick(double dt);
private:
Node* root_;
diff --git a/main.cpp b/main.cpp
index d723a1f..5224b29 100644
--- a/main.cpp
+++ b/main.cpp
@@ -26,36 +26,42 @@ int main(int argc, char** argv) {
std::cout << "N = " << N << std::endl;
/*
+ // print positions
for (unsigned i=0; i<N; ++i) {
for (unsigned j=0; j<3; ++j) {
std::cout << sim.getPositions()[3*i+j] << " ";
}
std::cout << std::endl;
}
- */
- try {
- // calculate mean interparticle distance
- double meanInterparticleDistance = sim.calculateMeanInterparticleDistance();
- std::cout << "Mean interparticle distance: " << meanInterparticleDistance << std::endl;
+ // calculate mean interparticle distance
+ double meanInterparticleDistance = sim.calculateMeanInterparticleDistance();
+ std::cout << "Mean interparticle distance: " << meanInterparticleDistance << std::endl;
+
+ // calculate forces and measure computation time
+ auto start = std::chrono::high_resolution_clock::now();
+ sim.calculateForces();
+ auto stop = std::chrono::high_resolution_clock::now();
- // calculate forces and measure computation time
- auto start = std::chrono::high_resolution_clock::now();
- sim.calculateForces();
- auto stop = std::chrono::high_resolution_clock::now();
+ auto duration = std::chrono::duration_cast<std::chrono::microseconds>(stop - start);
+ std::cout << "Computation Time: " << duration.count()/1000000.0 << " seconds" << std::endl;
- auto duration = std::chrono::duration_cast<std::chrono::microseconds>(stop - start);
- std::cout << "Computation Time: " << duration.count()/1000000.0 << " seconds" << std::endl;
+ // calculate mean force magnitude
+ double meanForceMagnitude = sim.calculateMeanForceMagnitude();
+ std::cout << "Mean force magnitude: " << meanForceMagnitude << std::endl;
- // calculate mean force magnitude
- double meanForceMagnitude = sim.calculateMeanForceMagnitude();
- std::cout << "Mean force magnitude: " << meanForceMagnitude << std::endl;
+ sim.write2file(sim.getForces(), "../out/forces.txt", 3);
+ */
- sim.write2file(sim.getForces(), "../out/forces.txt", 3);
+ try {
+ sim.runSimulation(dt, nSteps);
} catch (std::exception& e) {
std::cerr << e.what() << std::endl;
return 1;
}
+ // save state of simulation
+ sim.saveState2file(nSteps, "../out/state.txt");
+
return 0;
}
\ No newline at end of file
--
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