public void GiniClasificationImpurityCalculator_ImpurityImprovement()
{
var values = new double[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 2, 2, 2, 1, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, };
var unique = values.Distinct().ToArray();
var parentInterval = Interval1D.Create(0, values.Length);
var sut = new GiniClasificationImpurityCalculator();
sut.Init(unique, values, new double[0], parentInterval);
var impurity = sut.NodeImpurity();
sut.UpdateIndex(50);
var improvement1 = sut.ImpurityImprovement(impurity);
Assert.AreEqual(0.33333333333333343, improvement1, 0.000001);
sut.UpdateIndex(96);
var improvement2 = sut.ImpurityImprovement(impurity);
Assert.AreEqual(0.28047839506172845, improvement2, 0.000001);
}
public void GiniClasificationImpurityCalculator_ImpurityImprovement_Weighted()
{
var values = new double[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 2, 2, 2, 1, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, };
var unique = values.Distinct().ToArray();
var weights = values.Select(t => Weight(t)).ToArray();
var parentInterval = Interval1D.Create(0, values.Length);
var sut = new GiniClasificationImpurityCalculator();
sut.Init(unique, values, weights, parentInterval);
var impurity = sut.NodeImpurity();
sut.UpdateIndex(50);
var improvement1 = sut.ImpurityImprovement(impurity);
Assert.AreEqual(0.14015151515151511, improvement1, 0.000001);
sut.UpdateIndex(96);
var improvement2 = sut.ImpurityImprovement(impurity);
Assert.AreEqual(0.17358104858104859, improvement2, 0.000001);
}