private ScatterPointCollection CalculateResiduals()
{
var result = new List <ScatterplotPoint>();
for (var categoryIndex = 0; categoryIndex < _points.GroupsCount; categoryIndex++)
{
var category = _points.Groups[categoryIndex];
var categoryPoints = _points.Where(x => Math.Abs(x.Group) == category).ToArray();
var regression = new LinearRegressionBuilder(categoryPoints.Select(x => x.X).ToArray(), categoryPoints.Select(x => x.Y).ToArray()).Build();
foreach (var categoryPoint in categoryPoints)
{
var y = categoryPoint.Y - (regression.a0 + regression.a1 * categoryPoint.X);
result.Add(new ScatterplotPoint()
{
Group = categoryPoint.Group,
Date = categoryPoint.Date,
X = categoryPoint.X,
Y = y,
SubGroup = categoryPoint.SubGroup
});
}
}
return(new ScatterPointCollection(result));
}
private void DrawRegressionLine(ScatterplotPoint[] groupPoints, int groupIndex)
{
var regression = new LinearRegressionBuilder(groupPoints.Select(x => x.X).ToArray(), groupPoints.Select(x => x.Y).ToArray()).Build();
var categoryCalculator = new ScatterplotCalculator(groupPoints);
var x1 = CanvasCalculator.GetX(categoryCalculator.MinX);
var y1 = CanvasCalculator.GetY(regression.a0 + regression.a1 * categoryCalculator.MinX);
var x2 = CanvasCalculator.GetX(categoryCalculator.MaxX);
var y2 = CanvasCalculator.GetY(regression.a0 + regression.a1 * categoryCalculator.MaxX);
var vLine = new Line()
{
X1 = x1,
X2 = x2,
Y1 = y1,
Y2 = y2,
StrokeThickness = 2,
Stroke = new SolidColorBrush(new ColorPicker().Pick(groupIndex))
};
mainCanvas.Children.Add(vLine);
DisplayResult(groupIndex, regression);
}
