//classifies an instance - returns "" if the instance cannot be classified
private string classifyInstance(Instance instance, Tree tree)
{
Node selectedNode = db.Nodes.Single(i => i.ParentID < 1 && i.TreeID == tree.ID);
while (db.Nodes.Where(i => i.ParentID == selectedNode.ID).Count() > 0)
{
Boolean result = false;
List<Node> childNodes = db.Nodes.Where(i => i.ParentID == selectedNode.ID).ToList();
int j = 0;
while (result != true)
{
if (j >= childNodes.Count)
return ""; // this is the case where the instance cannot be classified, this can happen occasionally with nominal data
Node childNode = childNodes.ElementAt(j);
result = checkBranch(instance, selectedNode, childNode);
if (result == true)
{
selectedNode = childNodes.ElementAt(j);
}
j++;
}
}
return selectedNode.Attribute;
}
public ActionResult Enter(DataHolder d)
{
//this puts each line onto a string list, and also trims each line
string[] splitCharacters = new string[] { "\r\n" };
List<string> eachLine = d.DataString.Split(splitCharacters, StringSplitOptions.RemoveEmptyEntries).ToList();
eachLine = eachLine.Select(i => i.Trim()).ToList();
//gets @relation name
string datasetName = eachLine.ElementAt(0).Substring(9);
//add a dataset instance
DataSet dataset = new DataSet { Name = datasetName };
db.DataSets.Add(dataset);
db.SaveChanges();
//gets each attribute name
List<string> attributeNames = new List<string>();
foreach(var line in eachLine.Where(i=>i.Length>=10 && i.Substring(0,10) == "@attribute"))
{
attributeNames.Add(line.Split(' ')[1]);
}
int data = eachLine.IndexOf("@data");
foreach (var line in eachLine.Skip(data+1))
{
string instanceClass = line.Split(',')[attributeNames.Count - 1];
Instance instance = new Instance { Class = instanceClass, DataSetID = dataset.ID };
db.Instances.Add(instance);
db.SaveChanges();
foreach(var attributeName in attributeNames.TakeWhile(i=>i != attributeNames.Last()))
{
Models.Attribute attrObj = new Models.Attribute { AttributeName = attributeName, AttributeValue = line.Split(',')[attributeNames.IndexOf(attributeName)], InstanceID = instance.ID };
db.Attributes.Add(attrObj);
db.SaveChanges();
}
}
return RedirectToAction("Index");
}
//checks whether an instance meets a branchs conditions, eg if outlook==sunny
private Boolean checkBranch(Instance instance, Node parentNode, Node childNode)
{
string instanceAttributeValue = instance.Attributes.Single(i => i.AttributeName == parentNode.Attribute).AttributeValue;
switch(childNode.EdgeOperator)
{
case "==":
float n1;
float n2 = 0;
Boolean isNumber1 = float.TryParse(instanceAttributeValue, out n1);
Boolean isNumber2 = float.TryParse(childNode.EdgeValue, out n2);
if (isNumber1 == true)
if (n1 == n2)
return true;
else
return false;
else
if (childNode.EdgeValue == instanceAttributeValue)
return true;
else
return false;
case "<=":
float n3 = 0;
float n4 = 0;
Boolean isNumber3 = float.TryParse(instanceAttributeValue, out n3);
Boolean isNumber4 = float.TryParse(childNode.EdgeValue, out n4);
if (n3 <= n4)
return true;
else
return false;
case ">":
float n5 = 0;
float n6 = 0;
Boolean isNumber5 = float.TryParse(instanceAttributeValue, out n5);
Boolean isNumber6 = float.TryParse(childNode.EdgeValue, out n6);
if (n5 > n6)
return true;
else
return false;
}
return true;
}