/**
* <summary> The entropyForDiscreteAttribute method takes an attributeIndex and creates an List of DiscreteDistribution.
* Then loops through the distributions and calculates the total entropy.</summary>
*
* <param name="attributeIndex">Index of the attribute.</param>
* <returns>Total entropy for the discrete attribute.</returns>
*/
private double EntropyForDiscreteAttribute(int attributeIndex)
{
var sum = 0.0;
var distributions = _data.AttributeClassDistribution(attributeIndex);
foreach (var distribution in distributions)
{
sum += (distribution.GetSum() / _data.Size()) * distribution.Entropy();
}
return(sum);
}
