public void Process()
{
Attribute[] attributes =
StaticStorage.DataSet.Columns.Cast<DataColumn>().Where(m => !m.ColumnName.Equals(StaticStorage.TargetColum))
.Select(
m =>
new Attribute(m.ColumnName,
StaticStorage.DataSet.AsEnumerable()
.Select(i => i[m.ColumnName].ToString().Format())
.ToArray()
.Distinct()
.ToArray())).ToArray();
DecisionTreeId3 id3 = new DecisionTreeId3();
TreeNode root = id3.MountTree(StaticStorage.DataSet, StaticStorage.TargetColum, attributes);
PrintNode(root, "");
}
private TreeNode InternalMountTree(DataTable samples, string targetAttribute,
IReadOnlyCollection<Attribute> attributes)
{
if (AllSamplesPositives(samples, targetAttribute))
return new TreeNode(new Attribute(true));
if (AllSamplesNegatives(samples, targetAttribute))
return new TreeNode(new Attribute(false));
if (attributes.Count == 0)
return new TreeNode(new Attribute(GetMostCommonValue(samples, targetAttribute)));
_total = samples.Rows.Count;
_targetAttribute = targetAttribute;
_totalPositives = CountTotalPositives(samples);
_mEntropySet = CalcEntropy(_totalPositives, _total - _totalPositives);
Attribute bestAttribute = GetBestAttribute(samples, attributes);
TreeNode root = new TreeNode(bestAttribute);
DataTable aSample = samples.Clone();
foreach (string value in bestAttribute.Values)
{
// Select all the elements with this Attribute value
aSample.Rows.Clear();
DataRow[] rows = samples.Select(bestAttribute.AttributeName + " = " + "'" + value + "'");
foreach (DataRow row in rows)
aSample.Rows.Add(row.ItemArray);
// Select all the elements with this Attribute value
// Create a new list of attributes less the current Attribute that is the best Attribute
ArrayList aAttributes = new ArrayList(attributes.Count - 1);
foreach (
Attribute attribute in
attributes.Where(attribute => attribute.AttributeName != bestAttribute.AttributeName))
aAttributes.Add(attribute);
// Create a new list of attributes less the current Attribute that is the best Attribute
if (aSample.Rows.Count == 0)
return new TreeNode(new Attribute(GetMostCommonValue(aSample, targetAttribute)));
DecisionTreeId3 dc3 = new DecisionTreeId3();
TreeNode childNode = dc3.MountTree(aSample, targetAttribute,
(Attribute[])aAttributes.ToArray(typeof(Attribute)));
root.AddTreeNode(childNode, value);
}
return root;
}