public EulerState(EulerState other)
{
currentTime = other.currentTime;
N = other.N;
G = other.G;
eps = other.eps;
mass = new List <double>(other.mass);
position = new List <Vector3>(N);
velocity = new List <Vector3>(N);
for (int i = 0; i < N; i++)
{
position.Add(new Vector3(other.position[i]));
velocity.Add(new Vector3(other.velocity[i]));
}
}
public LeapFrogIntegrator(EulerState s)
: base(new LeapFrogState(s))
{
}
public EulerState(EulerState other)
{
currentTime = other.currentTime;
N = other.N;
G = other.G;
eps = other.eps;
mass = new List<double>( other.mass );
position = new List<Vector3>(N);
velocity = new List<Vector3>(N);
for (int i = 0; i < N; i++)
{
position.Add( new Vector3(other.position[i]));
velocity.Add( new Vector3(other.velocity[i]));
}
}
static void Main(string[] args)
{
bool cancelled = false;
Console.TreatControlCAsInput = false;
Console.CancelKeyPress += (s, ev) =>
{
Console.WriteLine("Ctrl+C pressed");
ev.Cancel = true;
cancelled = true;
};
Exception caught = null;
//Vector3.Test();
int N = 1000;
double G = 1.0;
double mass = 1.0;
double softeningLength = 0.1;
var startState = new EulerState(N, gravitationalConstant: G, defaultMass: mass, softeningLength: softeningLength);
StartUp_Ring(N, startState);
//StartUp_TwoOnCircle(startState);
//StartUp_ThreeOnEight(startState);
//StartUp_ColdCollapse8(startState);
INBodyIntegrator integrator = new LeapFrogIntegrator(startState);
//INBodyIntegrator integrator = new RungeKuttaIntegrator(startState, RungeKuttaIntegrator.Flavor.rk4);
//INBodyIntegrator integrator = new MultiStepIntegrator(startState, MultiStepIntegrator.Flavor.ms8);
const double delta = 0.001;
double oldTime;
double newTime;
INBodyState newState;
double ekin_start = startState.Ekin();
double epot_start = startState.Epot();
double etot_start = ekin_start + epot_start;
double ekin;
double epot;
double etot;
int count = 0;
string stateFileName = Path.Combine(Path.GetTempPath(), "data.txt");
Console.Error.WriteLine("Storing to \"{0}\"", stateFileName);
const int printModulus = 50;
const int saveModulus = 10;
var timeProgress = new Stopwatch();
var beginTime = DateTime.Now;
try
{
using (var stateFile = new System.IO.FileStream(stateFileName, FileMode.Create, FileAccess.Write, FileShare.Read))
using (var stateWriter = new StreamWriter(stateFile, Encoding.UTF8))
{
stateWriter.AutoFlush = true;
while (!cancelled && integrator.currentTMax < 240.0)
{
oldTime = integrator.currentTMax;
timeProgress.Start();
integrator.Progress(delta);
timeProgress.Stop();
newTime = integrator.currentTMax;
newState = integrator.currentState(newTime);
if (0 == (count % saveModulus) || 0 == (count % printModulus))
{
ekin = newState.Ekin();
epot = newState.Epot();
etot = ekin + epot;
if (0 == (count % printModulus))
{
Console.WriteLine("t:{0} Ekin:{1} Epot:{2} Etot:{3} Ediff:{4}", newTime, ekin, epot, etot, etot - etot_start);
}
if (0 == count % saveModulus)
{
var sb = new StringBuilder();
newState.Serialize(ekin, epot, sb);
stateWriter.Write(sb.ToString());
}
}
count++;
}
}
var endTime = DateTime.Now;
var elapsedTime = endTime - beginTime;
Console.Error.WriteLine("iterations per second: {0}", ((double)count) / elapsedTime.TotalSeconds);
Console.Error.WriteLine("{0} seconds total time", elapsedTime.TotalSeconds);
Console.Error.WriteLine("{0} seconds in Progress", timeProgress.Elapsed.TotalSeconds);
}
catch (Exception e)
{
caught = e;
}
finally
{
}
if (null != caught)
{
Console.Error.WriteLine(caught.ToString());
}
if (System.Diagnostics.Debugger.IsAttached)
{
Console.Error.WriteLine("Press ENTER to finish.");
Console.ReadLine();
}
}
private static void StartUp_TwoOnCircle(EulerState startState)
{
if (2 != startState.N)
throw new ArgumentOutOfRangeException("Need two bodies here.");
// two in a circle
startState.position[0][0] = -1.0;
startState.velocity[0][1] = -0.5;
startState.position[1][0] = 1.0;
startState.velocity[1][1] = 0.5;
}
private static void StartUp_ThreeOnEight(EulerState startState)
{
if (3 != startState.N)
throw new ArgumentOutOfRangeException("Need three bodies here.");
// three in an eight
startState.position[0] = new Vector3(0.9700436, -0.24308753);
startState.velocity[0] = new Vector3(0.466203685, 0.43236573);
startState.position[1] = new Vector3(-0.9700436, 0.24308753);
startState.velocity[1] = new Vector3(0.466203685, 0.43236573);
startState.position[2] = new Vector3();
startState.velocity[2] = new Vector3(-0.93240737, -0.86473146);
}
public LeapFrogState(EulerState state)
: base(state)
{
m_timeOfAccelerationCalculated = -1.0;
m_accelerations = null;
}
public MultiStepIntegrator(EulerState s, Flavor f)
{
state = new MultiStepState(s);
flavor = f;
}
public RungeKuttaIntegrator(EulerState s, Flavor f)
{
state = new LeapFrogState(s);
flavor = f;
}
public MultiStepIntegrator(EulerState s, Flavor f)
{
state = new MultiStepState(s);
flavor = f;
}
public MultiStepState(EulerState state)
: base(state)
{
}
public RungeKuttaIntegrator(EulerState s, Flavor f)
{
state = new LeapFrogState(s);
flavor = f;
}
public LeapFrogIntegrator(EulerState s)
: base(new LeapFrogState(s))
{
}
public EulerIntegrator(EulerState s)
{
state = s;
}
private static void StartUp_ColdCollapse8(EulerState startState)
{
if (8 != startState.N)
throw new ArgumentOutOfRangeException("Need eight bodies here.");
for (int i = 0; i < 8; i++)
{
double x = (i & 1) * 1.0;
double y = (i & 2) * 0.5;
double z = (i & 4) * 0.25;
startState.position[i] = new Vector3(x, y, z);
startState.velocity[i] = new Vector3();
startState.mass[i] = 1.0 + i * 0.1;
}
}
public LeapFrogState(EulerState state)
: base(state)
{
m_timeOfAccelerationCalculated = -1.0;
m_accelerations = null;
}
private static void StartUp_Ring(int N, EulerState startState)
{
var rand = new Random();
for (int particle = 0; particle < N; particle++)
{
double angle = particle * 2.0 * Math.PI / (N - 2);
double a = 0.01 * rand.NextDouble();
double b = 0.01 * rand.NextDouble();
double rFactor = 1.0 + (particle % 10) * 0.1;
startState.position[particle] = new Vector3(1.0 * Math.Sin(angle), 1.0 * Math.Cos(angle), 0.0) * rFactor;
startState.velocity[particle] = new Vector3( a - 0.1 * Math.Cos(angle), b + 0.1 * Math.Sin(angle), 0.0) * rFactor * rFactor;
//startState.position[particle] = new Vector3(2 - 4 * rand.NextDouble(), 2 - 4 * rand.NextDouble(), 0.0);
//startState.velocity[particle] = new Vector3(0.0, 0.0, 0.0);
startState.mass[particle] = 0.0005;
}
}
public MultiStepState(EulerState state)
: base(state)
{
}
public EulerIntegrator(EulerState s)
{
state = s;
}
