public void PrintDecisionTree(TreeNode treeNode)
{
if (treeNode.nodeData != Constants.Yes && treeNode.nodeData != Constants.No)
{
Console.WriteLine(treeNode.nodeData);
}
else
{
Console.WriteLine(" " + treeNode.nodeData);
}
if (treeNode.relations != null)
{
foreach (Relation relation in treeNode.relations)
{
Console.WriteLine(" " + relation.childEdge);
PrintDecisionTree(relation.childNode);
}
}
}
public void BuildDecisionTree(DataTable table, List<Attribute> attributes, Relation relation)
{
for (int i = 0; i < table.Columns.Count - 1; i++)
{
foreach (Attribute attribute in attributes)
{
if (table.Columns[i].Caption == attribute.attributeName)
{
for (int j = 0; j < table.Rows.Count; j++)
{
foreach (Option option in attribute.options)
{
if (table.Rows[j][i].ToString() == option.optionName)
{
if (table.Rows[j].Field<string>("Play") == Constants.Yes)
{
option.yesAmount++;
}
else if (table.Rows[j].Field<string>("Play") == Constants.No)
{
option.noAmount++;
}
}
}
}
foreach (Option option in attribute.options)
{
option.setInformationValue();
if (Double.IsNaN(option.informationValue))
{
option.informationValue = 0;
}
Console.WriteLine(option.informationValue);
}
attribute.setAverageInformationValue();
Console.WriteLine(" " + attribute.averageInformationValue);
}
}
}
Attribute choosenAttribute = attributes[0];
for (int i = 1; i < attributes.Count; i++)
{
if (attributes[i].averageInformationValue > choosenAttribute.averageInformationValue)
{
choosenAttribute = attributes[i];
}
}
Console.WriteLine(" " + choosenAttribute.averageInformationValue);
Console.WriteLine(Environment.NewLine + Environment.NewLine);
List<Relation> relations = new List<Relation>();
DataTable dataTable;
foreach (Option option in choosenAttribute.options)
{
if (option.informationValue != 0)
{
dataTable = table.Copy();
for (int i = 0; i < dataTable.Rows.Count; i++)
{
if (dataTable.Rows[i].Field<string>(choosenAttribute.attributeName) != option.optionName)
{
dataTable.Rows.Remove(dataTable.Rows[i]);
i--;
}
}
relations.Add(new Relation(null, option.optionName, dataTable));
}
else
{
string nodeData = "";
if (option.yesAmount == 0)
{
nodeData = Constants.No;
}
else if (option.noAmount == 0)
{
nodeData = Constants.Yes;
}
relations.Add(new Relation(new TreeNode(nodeData, null, null), option.optionName, null));
}
}
List<Attribute> tempAttributes = new List<Attribute>();
foreach (Attribute attribute in attributes)
{
if (attribute != choosenAttribute)
{
tempAttributes.Add(attribute);
}
}
TreeNode tempTreeNode = new TreeNode(choosenAttribute.attributeName, relations, tempAttributes);
this.treeNodes.Add(tempTreeNode);
if (relation != null)
{
relation.childNode = tempTreeNode;
}
foreach (Attribute attribute in attributes)
{
foreach (Option option in attribute.options)
{
option.yesAmount = 0;
option.noAmount = 0;
}
attribute.averageInformationValue = 0;
}
foreach (Relation newRelation in relations)
{
if (newRelation.childNode == null)
{
BuildDecisionTree(newRelation.dataTable, tempTreeNode.attributes, newRelation);
}
else
{
continue;
}
}
}
public Relation(TreeNode childNode, string childEdge, DataTable dataTable)
{
this.childNode = childNode;
this.childEdge = childEdge;
this.dataTable = dataTable;
}