protected CalibrationCurve AddRSquared(CalibrationCurve curve, IList <WeightedPoint> points)
{
List <double> yValues = new List <double>();
List <double> residuals = new List <double>();
foreach (var point in points)
{
double?yFitted = curve.GetY(point.X);
if (!yFitted.HasValue)
{
continue;
}
yValues.Add(point.Y);
residuals.Add(point.Y - yFitted.Value);
}
if (!residuals.Any())
{
return(curve);
}
double yMean = yValues.Average();
double totalSumOfSquares = yValues.Sum(y => (y - yMean) * (y - yMean));
double sumOfSquaresOfResiduals = residuals.Sum(r => r * r);
double rSquared = 1 - sumOfSquaresOfResiduals / totalSumOfSquares;
return(curve.ChangeRSquared(rSquared));
}
/// <summary>
/// Optimization function used when doing NelderMeadSimplex to find the best Limit of Detection.
/// </summary>
private static double LodObjectiveFunction(double lod, IList <WeightedPoint> weightedPoints)
{
CalibrationCurve calibrationCurve = GetCalibrationCurveWithLod(lod, weightedPoints);
if (calibrationCurve == null || !calibrationCurve.TurningPoint.HasValue)
{
return(double.MaxValue);
}
double totalDelta = 0;
double totalWeight = 0;
foreach (var pt in weightedPoints)
{
double delta = pt.Y - calibrationCurve.GetY(pt.X).Value;
totalWeight += pt.Weight;
totalDelta += pt.Weight * delta * delta;
}
return(totalDelta / totalWeight);
}
public CalibrationCurve AddRSquared(CalibrationCurve curve, IList<WeightedPoint> points)
{
List<double> yValues = new List<double>();
List<double> residuals = new List<double>();
foreach (var point in points)
{
double? yFitted = curve.GetY(point.X);
if (!yFitted.HasValue)
{
continue;
}
yValues.Add(point.Y);
residuals.Add(point.Y - yFitted.Value);
}
if (!residuals.Any())
{
return curve;
}
double yMean = yValues.Average();
double totalSumOfSquares = yValues.Sum(y => (y - yMean)*(y - yMean));
double sumOfSquaresOfResiduals = residuals.Sum(r => r*r);
double rSquared = 1 - sumOfSquaresOfResiduals/totalSumOfSquares;
return curve.ChangeRSquared(rSquared);
}
private LineItem CreateInterpolatedLine(CalibrationCurve calibrationCurve, double minX, double maxX, int pointCount, bool logPlot)
{
PointPairList pointPairList = new PointPairList();
for (int i = 0; i < pointCount; i++)
{
double x;
if (logPlot)
{
x = Math.Exp((Math.Log(minX)*(pointCount - 1 - i) + Math.Log(maxX)*i)/(pointCount - 1));
}
else
{
x = (minX*(pointCount - 1 - i) + maxX*i)/(pointCount - 1);
}
double? y = calibrationCurve.GetY(x);
if (y.HasValue)
{
pointPairList.Add(x, y.Value);
}
}
if (!pointPairList.Any())
{
return null;
}
return new LineItem(QuantificationStrings.Calibration_Curve, pointPairList, Color.Gray, SymbolType.None);
}