private DecisionAttributeOccurence GetRowsFromPath(List <int> path)
{
DecisionColumn currentDecisionColumn = null;
DecisionAttributeOccurence currentAttribute = null;
var positiveRows = new List <int>();
var negativeRows = new List <int>();
for (var i = 0; i < path.Count; i++)
{
if (i == 0 || i % 2 == 0)
{
currentDecisionColumn = DecisionColumns[path[i]];
}
else
{
currentAttribute = currentDecisionColumn?.Attributes[path[i]];
}
if (i <= 0)
{
continue;
}
if (positiveRows.Count < 1 && negativeRows.Count < 1)
{
positiveRows = currentAttribute.PositiveRowNumbers;
negativeRows = currentAttribute.NegativeRowNumbers;
}
else
{
positiveRows = positiveRows.Intersect(currentAttribute.PositiveRowNumbers).ToList();
negativeRows = negativeRows.Intersect(currentAttribute.NegativeRowNumbers).ToList();
}
}
return(new DecisionAttributeOccurence(currentAttribute.Value, positiveRows, negativeRows));
}
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);
}
