public void CalculateEquilibriumLP(List <MarketPoint> demandCurve, List <MarketPoint> supplyCurve)
{
var equilQ = MarketClearing.FindEquilibrium(supplyCurve.ToRectangularArray(), demandCurve.ToRectangularArray());
_equilibrium = new MarketPoint()
{
Price = (decimal)equilQ.eqPrice,
Volume = (decimal)equilQ.eqQuantity
};
}
public void CalculateEquilibrium()
{
/* Find bounding box */
var maxMinVolume = Math.Max(DemandCurve.Min(d => d.Volume), SupplyCurve.Min(d => d.Volume));
var minMaxVolume = Math.Min(DemandCurve.Max(d => d.Volume), SupplyCurve.Max(d => d.Volume));
var maxMinPrice = Math.Max(DemandCurve.Min(d => d.Price), SupplyCurve.Min(d => d.Price));
var minMaxPrice = Math.Min(DemandCurve.Max(d => d.Price), SupplyCurve.Max(d => d.Price));
var subDemandCurve = DemandCurve
.Where(d => maxMinVolume <= d.Volume && d.Volume <= minMaxVolume)
.Where(d => maxMinPrice <= d.Price && d.Price <= minMaxPrice)
.ToList();
var subSupplyCurve = SupplyCurve
.Where(d => maxMinVolume <= d.Volume && d.Volume <= minMaxVolume)
.Where(d => maxMinPrice <= d.Price && d.Price <= minMaxPrice)
.ToList();
try {
/* Run equilibrium procedure */
if (_eqlibriumAlgorithm == EquilibriumAlgorithm.CurveIntersection)
{
//naive inefficient method
CalculateEquilibriumBruteForce(subDemandCurve, subSupplyCurve);
}
else if (_eqlibriumAlgorithm == EquilibriumAlgorithm.WelfareMaximization)
{
//the main approached used in the literature
CalculateEquilibriumLP(subDemandCurve, subSupplyCurve);
}
} catch (Exception ex) {
//log it..
//should instead be null, so that it could go missing...
//adopt a simple interpolation technique...
_equilibrium = new MarketPoint()
{
Price = 0,
Volume = 0
};
}
}
//TODO: refactor to a more efficient algorithm! TOO SLOW... WAY TOO SLOW...
public void CalculateEquilibriumBruteForce(List <MarketPoint> demandCurve, List <MarketPoint> supplyCurve)
{
/* Brute force calculation for now */
var distances = new List <Tuple <int, int, double> >();
for (int i = 0; i < demandCurve.Count; i++)
{
var dPoint = demandCurve[i];
for (int j = 0; j < supplyCurve.Count; j++)
{
var sPoint = supplyCurve[j];
var l = Line.FindLength(dPoint.Volume, dPoint.Price, sPoint.Volume, sPoint.Price);
var t = new Tuple <int, int, double>(i, j, l);
distances.Add(t);
}
}
var smallestDistance = distances
.OrderBy(d => d.Item3)
.First();
var secondSmallestDistance = distances
.Where(d => d.Item3 > smallestDistance.Item3)
.OrderBy(d => d.Item3)
.First();
var iStart = smallestDistance.Item1;
var iEnd = secondSmallestDistance.Item1;
//should not happen
//DemandStart is closer to supply since Demand is downward sloping... so it's ordered decreasingly...
if (iStart == iEnd && iStart > 1)
{
iEnd = iStart - 1;
}
var jStart = smallestDistance.Item2;
var jEnd = secondSmallestDistance.Item2;
//should not happen,
if (jStart == jEnd && jStart < SupplyCurve.Count - 1)
{
jEnd = jStart + 1;
}
/* Interpolate to find equilibrium values */
var demandLine = new Line(
demandCurve[iStart].Volume, demandCurve[iStart].Price,
demandCurve[iEnd].Volume, demandCurve[iEnd].Price);
var supplyLine = new Line(
supplyCurve[jStart].Volume, supplyCurve[jStart].Price,
supplyCurve[jEnd].Volume, supplyCurve[jEnd].Price);
Point <decimal> intersection = demandLine.Intersect(supplyLine);
_equilibrium = new MarketPoint()
{
Price = intersection.Y,
Volume = intersection.X
};
}
public void CalculateEquilibrium()
{
/* Find bounding box */
var maxMinVolume = Math.Max(DemandCurve.Min(d => d.Volume), SupplyCurve.Min(d => d.Volume));
var minMaxVolume = Math.Min(DemandCurve.Max(d => d.Volume), SupplyCurve.Max(d => d.Volume));
var maxMinPrice = Math.Max(DemandCurve.Min(d => d.Price), SupplyCurve.Min(d => d.Price));
var minMaxPrice = Math.Min(DemandCurve.Max(d => d.Price), SupplyCurve.Max(d => d.Price));
var subDemandCurve = DemandCurve
.Where(d => maxMinVolume <= d.Volume && d.Volume <= minMaxVolume)
.Where(d => maxMinPrice <= d.Price && d.Price <= minMaxPrice)
.ToList();
var subSupplyCurve = SupplyCurve
.Where(d => maxMinVolume <= d.Volume && d.Volume <= minMaxVolume)
.Where(d => maxMinPrice <= d.Price && d.Price <= minMaxPrice)
.ToList();
try {
/* Run equilibrium procedure */
if (_eqlibriumAlgorithm == EquilibriumAlgorithm.CurveIntersection)
//naive inefficient method
CalculateEquilibriumBruteForce(subDemandCurve, subSupplyCurve);
else if (_eqlibriumAlgorithm == EquilibriumAlgorithm.WelfareMaximization)
//the main approached used in the literature
CalculateEquilibriumLP(subDemandCurve, subSupplyCurve);
} catch(Exception ex) {
//log it..
//should instead be null, so that it could go missing...
//adopt a simple interpolation technique...
_equilibrium = new MarketPoint()
{
Price = 0,
Volume = 0
};
}
}
//TODO: refactor to a more efficient algorithm! TOO SLOW... WAY TOO SLOW...
public void CalculateEquilibriumBruteForce(List<MarketPoint> demandCurve, List<MarketPoint> supplyCurve)
{
/* Brute force calculation for now */
var distances = new List<Tuple<int,int,double>>();
for (int i = 0; i < demandCurve.Count; i++)
{
var dPoint = demandCurve[i];
for (int j = 0; j < supplyCurve.Count; j++)
{
var sPoint = supplyCurve[j];
var l = Line.FindLength(dPoint.Volume, dPoint.Price, sPoint.Volume, sPoint.Price);
var t = new Tuple<int, int, double>(i, j, l);
distances.Add(t);
}
}
var smallestDistance = distances
.OrderBy(d=>d.Item3)
.First();
var secondSmallestDistance = distances
.Where(d=>d.Item3 > smallestDistance.Item3)
.OrderBy(d => d.Item3)
.First();
var iStart = smallestDistance.Item1;
var iEnd = secondSmallestDistance.Item1;
//should not happen
//DemandStart is closer to supply since Demand is downward sloping... so it's ordered decreasingly...
if (iStart == iEnd && iStart > 1)
iEnd = iStart - 1;
var jStart = smallestDistance.Item2;
var jEnd = secondSmallestDistance.Item2;
//should not happen,
if (jStart == jEnd && jStart < SupplyCurve.Count - 1)
jEnd = jStart + 1;
/* Interpolate to find equilibrium values */
var demandLine = new Line(
demandCurve[iStart].Volume, demandCurve[iStart].Price,
demandCurve[iEnd].Volume, demandCurve[iEnd].Price);
var supplyLine = new Line(
supplyCurve[jStart].Volume, supplyCurve[jStart].Price,
supplyCurve[jEnd].Volume, supplyCurve[jEnd].Price);
Point<decimal> intersection = demandLine.Intersect(supplyLine);
_equilibrium = new MarketPoint()
{
Price = intersection.Y,
Volume = intersection.X
};
}
public void CalculateEquilibriumLP(List<MarketPoint> demandCurve, List<MarketPoint> supplyCurve)
{
var equilQ = MarketClearing.FindEquilibrium(supplyCurve.ToRectangularArray(), demandCurve.ToRectangularArray());
_equilibrium = new MarketPoint()
{
Price = (decimal)equilQ.eqPrice,
Volume = (decimal)equilQ.eqQuantity
};
}