private void GetOccurencesList(int position)
{
var uniques = GetUniqueValues(position);
foreach (var unique in uniques)
{
var rows = GetRowNumbersForOccurences(unique);
LastRowOccurences.Add(new Occurence(unique, DecisionRows.Count(array => array[position] == unique), rows));
}
ShowLastDigitsAndOccurences();
ShowDecisionsCountMessage();
}
public List <DecisionColumn> CalculateDecisions()
{
DecisionColumns = new List <DecisionColumn>();
for (int i = 0; i < DecisionRows.First().Length - 1; i++)
{
var decisionColumn = new DecisionColumn();
var uniqueValues = DecisionRows.Select(value => value[i]).Distinct().ToList();
foreach (var uniqueValue in uniqueValues)
{
var decisionAttributeOccurence = new DecisionAttributeOccurence(uniqueValue);
for (int j = 0; j < DecisionRows.Count; j++)
{
if (DecisionRows[j][i] == uniqueValue)
{
var lastColumnDecision = LastRowOccurences.Where(occurence => occurence.RowNumbers.Contains(j + 1)).Select(occurence => occurence.Decision).First();
if (lastColumnDecision == DecisionType.Positive)
{
decisionAttributeOccurence.PositiveRowNumbers.Add(j + 1);
}
else
{
decisionAttributeOccurence.NegativeRowNumbers.Add(j + 1);
}
}
}
decisionColumn.Attributes.Add(decisionAttributeOccurence);
}
DecisionColumns.Add(decisionColumn);
}
CalculateColumnsEntropies();
CalculateColumnInformationGain();
var rejectedList = DecisionColumns.Where(column => AlreadyUsedIndexes.Contains((int)column.ColumnIndex));
var bestOne = DecisionColumns.Except(rejectedList).MaxBy(column => column.InformationGain); //Nieużyta z największym przyrostem informacji
var indexes = new List <int> {
(int)bestOne.ColumnIndex
};
DoUnknownThing(indexes, null);
return(DecisionColumns);
}
private double CalculateTotalEntropy()
{
var decisions = LastRowOccurences.Sum(occurence => occurence.Amount);
return(LastRowOccurences.Sum(occurence => (double)occurence.Amount / decisions * occurence.Entropy));
}
