public void Compute(ITime targetTime)
{
HandleExchangeItemsBeforeCompute();
double tStep = parameterValues[TimeStepId];
int nsteps = (int)Math.Round((targetTime.MJD - t) / tStep);
IVector x = state;
IVector xn;
for (int i = 0; i < nsteps; i++)
{
// --> Runge-Kutta
// System.out.print("step :"+i+" ");
// dx0 = dx(x,t);
IVector dxdt0 = Dx(x, t);
// dx1 = dx(x+0.5*dx0,t+0.5*dt);
xn = x.Clone();
xn.Axpy(0.5 * tStep, dxdt0);
IVector dxdt1 = Dx(xn, t + 0.5 * tStep);
// dx2 = dx(t+0.5*dt,x+0.5*dx1);
xn = x.Clone();
xn.Axpy(0.5 * tStep, dxdt1);
IVector dxdt2 = Dx(xn, t + 0.5 * tStep);
// dx3 = dx(t+1.0*dt,x+1.0*dx2);
xn = x.Clone();
xn.Axpy(1.0 * tStep, dxdt2);
IVector dxdt3 = Dx(xn, t + 0.5 * tStep);
// x = x + 1/6*dt*(dx0+2*dx1+2*dx2+dx3);
x.Axpy(1.0 / 6.0 * tStep, dxdt0);
x.Axpy(2.0 / 6.0 * tStep, dxdt1);
x.Axpy(2.0 / 6.0 * tStep, dxdt2);
x.Axpy(1.0 / 6.0 * tStep, dxdt3);
t += tStep;
timeStep++;
// Console.Out.WriteLine(">>>>>>> t="+t+" x="+x);
if (storeObs)
{
// store all states if this is requested
tStore.Add(t);
xStore.Add(x.Clone());
iStore.Add(timeStep);
}
if (outputLevel != OutputLevel.Suppress)
{
ResultsJ2N.PutValue("model_time", t, MessageType.Step);
ResultsJ2N.PutValue("x", x, MessageType.Step);
}
}
state.Values = x.Values;
t += tStep;
UpdateExchangeItemsAfterCompute();
}
public IModelState LoadPersistentState(string persistentStateFile)
{
VectorJ2N x;
double persistentTimeStamp;
int timestep;
try
{
if (!File.Exists(persistentStateFile))
{
throw new Exception("Could not find file for saved state:" + persistentStateFile);
}
// read state and time from file
StreamReader buff = new StreamReader(persistentStateFile);
// Read and parse first line
string line = buff.ReadLine();
string[] keyValuePair = line.Split(new[] { '=' }); // expect eg x=[1.0,2.0,3.0]
x = new VectorJ2N(keyValuePair[1]);
// Read and parse second line
line = buff.ReadLine();
keyValuePair = line.Split(new[] { '=' }); // expect eg t=1.0
persistentTimeStamp = Double.Parse(keyValuePair[1]);
// Read and parse third line
line = buff.ReadLine();
keyValuePair = line.Split(new[] { '=' }); // expect eg timestep=3
timestep = Int32.Parse(keyValuePair[1]);
buff.Close();
}
catch (IOException e)
{
ResultsJ2N.PutMessage("Exception: " + e.Message);
throw new Exception("Error reading restart file for model");
}
// set state and time
SavedState saveState = new SavedState();
saveState.time = persistentTimeStamp;
saveState.timestep = timestep;
saveState.state = x;
return(saveState);
}
public void Initialize(string workingDir, string configstring)
{
//
// GENERIC PART
//
// Instance counter
thisInstanceNumber = nextinstanceNumber;
nextinstanceNumber++;
//now parse configuration
//
// <?xml version="1.0" encoding="UTF-8"?>
// <oscillatorConfig>
//<simulationTimespan>[0.0,0.05,10.0]</simulationTimespan>
//<parameters names="t_damp,omega">[8.0,1.5708]</parameters>
//<parameterUncertainty names="t_damp,omega">[1.0,0.1257]</parameterUncertainty>
//<systemNoise>{[0.0,0.0],[0.3,0.3]}</systemNoise>
//<initialState>[0.8,0.0]</initialState>
//<initialStateUncertainty>[0.8,0.8]</initialStateUncertainty>
//</oscillatorConfig>
//
ResultsJ2N.PutMessage("configstring = " + configstring);
conf = new ConfigTreeJ2N(workingDir, configstring);
//
// parse simulationTimespan
//
// <simulationTimespan>[0.0,0.05,10.0]</simulationTimespan>
string timespanstring = conf.GetContentstring("simulationTimespan");
if (timespanstring != null)
{
IVector timespanVector = new VectorJ2N(timespanstring);
AddOrSetParameter(StartTimeId, timespanVector.GetValue(0));
AddOrSetParameter(TimeStepId, timespanVector.GetValue(1));
AddOrSetParameter(StopTimeId, timespanVector.GetValue(2));
ResultsJ2N.PutMessage("simulationTimespan =" + timespanVector);
}
// start at initial time
t = parameterValues[StartTimeId];
timeStep = 0; //counter starts at 0
//
// parse parameters
//
string namestring = conf.GetAsstring("parameters@names", "");
string parstring = conf.GetContentstring("parameters");
if (parstring != null)
{
IVector parValues = new VectorJ2N(parstring);
ResultsJ2N.PutMessage("parameters@names =" + namestring + " parameters=" + parValues);
string[] names = namestring.Split(new[] { ',' });
for (int i = 0; i < names.Length; i++)
{
if (!parameterValues.ContainsKey(names[i]))
{
parameterValues.Add(names[i], parValues.GetValue(i));
}
else
{
ResultsJ2N.PutMessage("parameter " + names[i] + " was not recognized. Value was ignored.");
}
}
}
CreateExchangeItems();
AddExchangeItemsAfterInitialisation();
}
