public void OnlyPredator_Test()
{
var stateAfterTimeStep = new Dictionary <double, (ulong PreyDensity, ulong PredatorDensity)>();
double timeStep = 0.0;
double deltaTime = 1.0;
ulong initialPreyDensity = 0;
ulong initialPredatorDensity = 1000;
var model = new LotkaVolterraModel(initialPreyDensity, initialPredatorDensity)
{
PreyGrowthRatio = 0.5,
PredationRate = 0.5,
PredatorMortalityRate = 0.5,
PredatorReproductionRate = 0.5
};
model.Calculate(deltaTime);
timeStep += deltaTime;
stateAfterTimeStep.Add(timeStep, (model.PreyDensity, model.PredatorDensity));
model.Calculate(deltaTime);
timeStep += deltaTime;
stateAfterTimeStep.Add(timeStep, (model.PreyDensity, model.PredatorDensity));
Assert.AreEqual((ulong)0, stateAfterTimeStep[1 * deltaTime].PreyDensity);
Assert.AreEqual((ulong)500, stateAfterTimeStep[1 * deltaTime].PredatorDensity);
Assert.AreEqual((ulong)0, stateAfterTimeStep[2 * deltaTime].PreyDensity);
Assert.AreEqual((ulong)250, stateAfterTimeStep[2 * deltaTime].PredatorDensity);
}
public void DeltaTimeZero_Test()
{
ulong initialPreyDensity = 100;
ulong initialPredatorDensity = 10;
var model = new LotkaVolterraModel(initialPreyDensity, initialPredatorDensity);
model.Calculate(0);
Assert.AreEqual(initialPreyDensity, model.PreyDensity);
Assert.AreEqual(initialPredatorDensity, model.PredatorDensity);
}
public void BothExist_Test()
{
var stateAfterTimeStep = new Dictionary <double, (ulong PreyDensity, ulong PredatorDensity)>();
double timeElapsed = 0.0;
double deltaTime = 1.0 / 12.0;
ulong initialPreyDensity = 100;
ulong initialPredatorDensity = 10;
var model = new LotkaVolterraModel(initialPreyDensity, initialPredatorDensity)
{
PreyGrowthRatio = 0.1,
PredationRate = 0.25,
PredatorMortalityRate = 0.05,
PredatorReproductionRate = 0.25
};
model.Calculate(deltaTime);
timeElapsed += deltaTime;
stateAfterTimeStep.Add(timeElapsed, (model.PreyDensity, model.PredatorDensity));
model.Calculate(deltaTime);
timeElapsed += deltaTime;
stateAfterTimeStep.Add(timeElapsed, (model.PreyDensity, model.PredatorDensity));
model.Calculate(deltaTime);
timeElapsed += deltaTime;
stateAfterTimeStep.Add(timeElapsed, (model.PreyDensity, model.PredatorDensity));
Assert.AreEqual((ulong)80, stateAfterTimeStep[1 * deltaTime].PreyDensity);
Assert.AreEqual((ulong)15, stateAfterTimeStep[1 * deltaTime].PredatorDensity);
Assert.AreEqual((ulong)55, stateAfterTimeStep[2 * deltaTime].PreyDensity);
Assert.AreEqual((ulong)21, stateAfterTimeStep[2 * deltaTime].PredatorDensity);
Assert.AreEqual((ulong)31, stateAfterTimeStep[3 * deltaTime].PreyDensity);
Assert.AreEqual((ulong)26, stateAfterTimeStep[3 * deltaTime].PredatorDensity);
}