public void EntropyH_Values()
{
Assert.AreEqual(0.0F, GeneralUtils.EntropyH(0), EPS);
Assert.AreEqual(0.33219280948874F, GeneralUtils.EntropyH(0.1F), EPS);
Assert.AreEqual(0.46438561897747F, GeneralUtils.EntropyH(0.2F), EPS);
Assert.AreEqual(0.52108967824986F, GeneralUtils.EntropyH(0.3F), EPS);
Assert.AreEqual(0.52877123795494F, GeneralUtils.EntropyH(0.4F), EPS);
Assert.AreEqual(0.5F, GeneralUtils.EntropyH(0.5F), EPS);
Assert.AreEqual(0.44217935649972F, GeneralUtils.EntropyH(0.6F), EPS);
Assert.AreEqual(0.36020122098083F, GeneralUtils.EntropyH(0.7F), EPS);
Assert.AreEqual(0.25754247590989F, GeneralUtils.EntropyH(0.8F), EPS);
Assert.AreEqual(0.13680278410054F, GeneralUtils.EntropyH(0.9F), EPS);
Assert.AreEqual(0.0F, GeneralUtils.EntropyH(1.0F), EPS);
}
public override double Calculate(Predicate <TObj> pattern, ClassifiedSample <TObj> sample)
{
var clsInfos = new Dictionary <Class, ClassBag>();
int p = 0;
var l = sample.Count;
foreach (var pData in sample)
{
var cls = pData.Value;
ClassBag bag;
if (!clsInfos.TryGetValue(cls, out bag))
{
bag = new ClassBag();
clsInfos.Add(cls, bag);
}
bag.Pc += 1;
if (pattern(pData.Key))
{
p += 1;
bag.pc += 1;
}
}
var result = 0.0D;
foreach (var cData in clsInfos)
{
var bag = cData.Value;
result += GeneralUtils.EntropyH(bag.Pc / l);
result += (p == 0) ? 0 : -(double)p / l * GeneralUtils.EntropyH(bag.pc / p);
result += (p == l) ? 0 : -(double)(l - p) / l * GeneralUtils.EntropyH((bag.Pc - bag.pc) / (l - p));
}
return(result);
}
