private async Task OnClassifyLogisticRegression()
{
try
{
var logisticRegression = new LogisticRegression(FirstClass, SecondClass);
logisticRegression.Train(0.01);
var stopwatch = new Stopwatch();
await Task.Run(() =>
{
stopwatch.Start();
for (var i = 0; i < 5000; i++)
{
var randomPointX = random.NextDouble() * (PlotModel.Axes[0].Maximum - PlotModel.Axes[0].Minimum) + PlotModel.Axes[0].Minimum;
var randomPointY = random.NextDouble() * (PlotModel.Axes[1].Maximum - PlotModel.Axes[1].Minimum) + PlotModel.Axes[1].Minimum;
var logisticRegressionProbabilityResult = logisticRegression.Classify(randomPointX, randomPointY);
if (logisticRegressionProbabilityResult > 0.5)
{
FirstClassScatterSeries.Points.Add(new ScatterPoint(randomPointX, randomPointY, 4, double.NaN, FirstClass.Id));
}
else
{
SecondClassScatterSeries.Points.Add(new ScatterPoint(randomPointX, randomPointY, 4, double.NaN, FirstClass.Id));
}
if (stopwatch.Elapsed > TimeSpan.FromMilliseconds(100))
{
PlotModel.InvalidatePlot(true);
stopwatch.Restart();
}
}
});
PlotModel.InvalidatePlot(true);
}
catch (Exception e)
{
MessageBox.Show(e.Message, "Error", MessageBoxButton.OK, MessageBoxImage.Error);
}
}
private async Task DrawRoc( )
{
CanInteract = false;
Status = "Training classifier...";
await Task.Factory.StartNew(() => logistic.Fit(train,
trainAns.Select(x => isAimClass(x))
.ToArray( )));
var series = new LineSeries( )
{
Smooth = false, LineStyle = LineStyle.Solid
};
Status = "Iterating over thresholds...";
for (double tr = -10; tr <= 10; tr += 0.005)
{
logistic.Threshold = tr;
var ans = await Task.Factory.StartNew(() => logistic.Classify(test));
series.Points.Add(new DataPoint(CalcFPR(ans), CalcTPR(ans)));
}
var newModel = new PlotModel
{
Title = $"ROC for class {CurrentClass}",
};
newModel.Series.Add(series);
newModel.Series.Add(new FunctionSeries(x => x, 0, 1, 0.01));
Model = newModel;
NotifyOfPropertyChange(() => Model);
var plot = series.Points.Distinct( ).OrderBy(x => x.X * 10 + x.Y).ToList( );
Status = $"Area under curve: {CalcArea( plot )}";
CanInteract = true;
}
