/// <summary>
/// Performs the calibration
/// </summary>
/// <param name="positions">list of gaze positions in of calibration points in order in which they were presented</param>
public async void Calibrate(List <Point> positions)
{
calibrationPositions = positions;
double[] pupilX = new double[positions.Count];
double[] pupilY = new double[positions.Count];
double[] screenX = new double[positions.Count];
double[] screenY = new double[positions.Count];
for (int i = 0; i < positions.Count; i++)
{
pupilX[i] = positions[i].X;
pupilY[i] = positions[i].Y;
// remember this indexing exists because the order in which the points are presented is
// not the same as they are generated by the loop
screenX[i] = calibrationParameters.calibrationPoints[calibrationParameters.calibrationSequence[i].Index].X;
screenY[i] = calibrationParameters.calibrationPoints[calibrationParameters.calibrationSequence[i].Index].Y;
}
//
await Task.Run(() =>
{
xInterpolator = RBF2D.SearchHyperparameters(pupilX, pupilY, screenX,
calibrationParameters.baseRadiusRange, calibrationParameters.numBaseRadii,
calibrationParameters.numLayersRange, calibrationParameters.regularizerRange,
calibrationParameters.numRegularizers,
calibrationParameters.logSpaceRegularizers);
yInterpolator = RBF2D.SearchHyperparameters(pupilX, pupilY, screenY,
calibrationParameters.baseRadiusRange, calibrationParameters.numBaseRadii,
calibrationParameters.numLayersRange, calibrationParameters.regularizerRange,
calibrationParameters.numRegularizers,
calibrationParameters.logSpaceRegularizers);
});
OnCalibrationFinished();
}
public RBF2DTo2D(double[] x, double[] y, double[] valueX, double[] valueY)
{
xInterpolator = new RBF2D(x, y, valueX);
yInterpolator = new RBF2D(x, y, valueY);
dataX = x;
dataY = y;
dataValueX = valueX;
dataValueY = valueY;
}
/// <summary>
/// Performs leave-one-out selection of best hyperparameter values for the RBF
/// </summary>
/// <param name="x">data X</param>
/// <param name="y">data Y</param>
/// <param name="value">data values at (X, Y)</param>
/// <param name="baseRadiusRange">range of values for the base radius, must > 0</param>
/// <param name="numBaseRadii">number of values for the base radius</param>
/// <param name="numLayersRange">number of layers, must be > 0</param>
/// <param name="regularizerRange">range of regularizers to use, must be >= 0</param>
/// <param name="numRegularizers">number of regularizers</param>
/// <param name="logSpaceRegularizers">log space instead of linearly space regularizers?</param>
/// <returns>RBF fit on all of the data using the parameter that generated the lowest sum of squares loss</returns>
public static RBF2D SearchHyperparameters(double[] x, double[] y, double[] value, Tuple <double, double> baseRadiusRange, int numBaseRadii,
Tuple <int, int> numLayersRange, Tuple <double, double> regularizerRange, int numRegularizers, bool logSpaceRegularizers)
{
RBF2D best = null;
double bestError = Double.PositiveInfinity;
List <double> regularizers = new List <double>
{
regularizerRange.Item1
};
double start = regularizerRange.Item1;
double end = regularizerRange.Item2;
if (logSpaceRegularizers)
{
start = start == 0 ? -6 : Math.Log(start);
end = Math.Log(end);
}
foreach (double regularizer in Num.linspace(start, end, regularizerRange.Item1 == 0 ? numRegularizers - 1 : numRegularizers))
{
regularizers.Add(logSpaceRegularizers ? Math.Pow(10, regularizer) : regularizer);
}
object parallelLock = new object();
foreach (double baseRadius in Num.linspace(baseRadiusRange.Item1, baseRadiusRange.Item2, numBaseRadii))
{
for (int numLayers = numLayersRange.Item1; numLayers < numLayersRange.Item2 + 1; numLayers++)
{
Parallel.ForEach(regularizers, (double regularizer) =>
{
RBF2D RBF = new RBF2D(x, y, value)
{
baseRadius = baseRadius,
numLayers = numLayers,
regularizer = regularizer
};
double error = RBF.CrossValidate();
lock (parallelLock)
{
if (error < bestError)
{
best = RBF;
bestError = error;
}
}
});
}
}
return(best);
}
public RBF2DTo2D()
{
xInterpolator = new RBF2D();
yInterpolator = new RBF2D();
}