public static void AddRandomEdge(CircleGraph graph, Node node, double[] vars)
{
List <Node> others = new List <Node>();
if (node.ConnectedTo(graph.Adjacent(node, 1)))
{
others.Add(graph.Adjacent(node, 1));
}
if (node.ConnectedTo(graph.Adjacent(node, -1)))
{
others.Add(graph.Adjacent(node, -1));
}
if (node.ConnectedTo(graph.Adjacent(node, 2)))
{
others.Add(graph.Adjacent(node, 2));
}
if (node.ConnectedTo(graph.Adjacent(node, -2)))
{
others.Add(graph.Adjacent(node, -2));
}
Node rand = null;
do
{
rand = graph.RandomNode();
}while (rand == node || others.Contains(rand));
others.Add(rand);
node.To(others[randgen.Next(others.Count)], 1.0);
}
public static double[,] Run()
{
const int count = 100;
const double timescale = 1.0 / 4;
CircleGraph firms = new CircleGraph(count, 4);
firmCapital = new NodeStock("Capital (K)", firms.GraphStack, new NodeConstant("initial", firms.GraphStack, NodeRandomInitial, GlobalDimensions.get("k")));
TemporalVariable firmProduction = new Function("Production (Y)", x => timescale * x[0] * Math.Pow(x[1], x[2]),
GlobalDimensions.get("k"), (firms.NodeEdgeCount() + 1), firmCapital, new Constant("Preference (alpha)", .3, Dimensionless.Instance));
Constant savingsRate = new Constant("Savings Rate (s)", .1, GlobalDimensions.Time.RaisedTo(-1));
firms.AddAction(new StepNodeAction(.1 * timescale, AddRandomEdge)); // technological advancement
firms.AddAction(new StepNodeAction(GrowOrDie, new PassiveDelay(firmProduction, 1), savingsRate, firmCapital, new Constant("Depreciation Rate (delta)", .1 * timescale, GlobalDimensions.Time.RaisedTo(-1))));
double[,] result = new double[1000, 3];
for (int tt = 0; tt < 1000; tt++)
{
collapses = 0;
result[tt, 0] = firms.Sum(firmCapital).Evaluate(tt);
result[tt, 1] = (1 - savingsRate.Evaluate(tt)) * firms.Sum(firmProduction).Evaluate(tt);
result[tt, 2] = collapses;
}
return(result);
}
public void Perform(CircleGraph graph, Node node, double time)
{
if (prob == 1.0 || randgen.NextDouble() <= prob)
{
double[] vals = new double[args.Length];
for (int ii = 0; ii < args.Length; ii++)
{
vals[ii] = args[ii].Evaluate(time);
}
action(graph, node, vals);
}
}
public static void GrowOrDie(CircleGraph graph, Node node, double[] args)
{
double growth = args[0] * args[1]; // production * savings
double decay = args[2] * args[3]; // capital * depeciation
if (growth < decay)
{
growth = 0; // Stalled Growth (dK=0)
}
double collapse = decay / (args[2] + growth);
if (randgen.NextDouble() < collapse)
{
node.RemoveAllEdges();
growth = -args[2] + NodeRandomInitial(node, 0);
collapses++;
}
firmCapital.Add(node, growth);
}
public static double[,] Run()
{
const int count = 100;
const double timescale = 1.0 / 4;
// First get this working like SolowModel, then move into SOCSolowModel
Stock labor = new SimplePopulationStock("Labor (L)", 10000, .01 * timescale);
TemporalVariable firmLabor = labor / new Constant("Firms", count, Dimensionless.Instance);
CircleGraph firms = new CircleGraph(count, 4);
firmCapital = new NodeStock("Capital (K)", firms.GraphStack, new NodeConstant("initial", firms.GraphStack, NodeRandomInitial, GlobalDimensions.get("k")));
TemporalVariable firmEffectiveLabor = firmLabor * (firms.NodeEdgeCount() + 1);
TemporalVariable firmProduction = new Function("Production (Y)", x => timescale * Math.Pow(count * x[0], x[2]) * Math.Pow(count * x[1], (1 - x[2])),
GlobalDimensions.get("k"), firmCapital, firmEffectiveLabor, new Constant("Preference (alpha)", .3, Dimensionless.Instance));
Constant savingsRate = new Constant("Savings Rate (s)", .1, GlobalDimensions.Time.RaisedTo(-1));
firms.AddAction(new StepNodeAction(.1 * timescale, AddRandomEdge)); // technological advancement
firms.AddAction(new StepNodeAction(GrowOrDie, new PassiveDelay(firmProduction, 1), savingsRate, firmCapital, new Constant("Depreciation Rate (delta)", .1 * timescale, GlobalDimensions.Time.RaisedTo(-1))));
//TemporalVariable capitalPerEffectiveLaborer = firms.Sum(firmCapital) / firms.Sum(firmEffectiveLabor);
TemporalVariable capitalPerLaborer = firms.Sum(firmCapital) / firms.Sum(firmLabor);
TemporalVariable productionPerLaborer = firms.Sum(firmProduction) / firms.Sum(firmLabor);
double[,] result = new double[1000, 4];
for (int tt = 0; tt < 1000; tt++)
{
collapses = 0;
result[tt, 0] = capitalPerLaborer.Evaluate(tt);
result[tt, 1] = (1 - savingsRate.Evaluate(tt)) * productionPerLaborer.Evaluate(tt);
result[tt, 2] = labor.Evaluate(tt);
result[tt, 3] = collapses;
}
return(result);
}
public HeartBeatVariable(CircleGraph graph)
: base("heartbeat", Dimensionless.Instance)
{
this.graph = graph;
this.lastHeartbeat = 0;
}