public object Calculate(CustomDataElement testDataObject, int k, List <string> fileData, string[] selectColumns, string classColumn)
{
var data = DataSetup.SetUpData(fileData, selectColumns, classColumn);
var neighbors = GetNeighbors(data, testDataObject, k);
var type = SelectType(neighbors);
return(type);
}
/// <summary>
/// Calculates distance between points using Euclide algorithm.
/// </summary>
/// <param name="columnElements"> points</param>
/// <param name="testDataObject"> testing object</param>
/// <returns> distance between elements</returns>
private double CalculateDistance(CustomDataElement testDataObject, List <double> columnElements)
{
var distance = 0.0;
for (int i = 0; i < testDataObject.Elements.Count; i++)
{
distance += Math.Pow((columnElements[i] - testDataObject.Elements[i]), 2);
}
return(Math.Sqrt(distance));
}
/// <summary>
/// Main calculation method.
/// </summary>
/// <param name="testDataElement">new test object data</param>
/// <param name="fileData">input data</param>
/// <param name="selectColumns">selected data column numbers</param>
/// <param name="classColumn">class column number</param>
/// <returns></returns>
public string Calculate(CustomDataElement testDataElement, List <string> fileData, string[] selectColumns, string classColumn)
{
var data = DataSetup.SetUpData(fileData, selectColumns, classColumn);
var classDictionary = SeparateData(data);
var summary = GetClassSummary(classDictionary);
var probabilities = GetProbabilities(summary, testDataElement);
var prediction = GetPrediction(probabilities);
return(prediction.Key);
}
/// <summary>
/// Returns reighbor list using selected test data.
/// </summary>
/// <returns> neighbor list </returns>
private List <Distances> GetNeighbors(List <CustomDataElement> data, CustomDataElement testDataObject, int k)
{
List <Distances> distances = new List <Distances>();
List <Distances> neighbors = new List <Distances>();
foreach (var obj in data)
{
var distance = CalculateDistance(testDataObject, obj.Elements);
distances.Add(new Distances()
{
Data = obj, Distance = distance
});
}
List <Distances> sortedDistances = distances.OrderBy(t => t.Distance).ToList();
for (int i = 0; i < k; i++)
{
neighbors.Add(sortedDistances[i]);
}
return(neighbors);
}
/// <summary>
/// Calculates every class probability by new test object
/// </summary>
/// <param name="summary">list</param>
/// <param name="testDataElement"> new test object parameters </param>
/// <returns>probabilities</returns>
private Dictionary <string, double> GetProbabilities(Dictionary <string, List <SummaryListElement> > summary, CustomDataElement testDataElement)
{
Dictionary <string, double> probabilities = new Dictionary <string, double>();
foreach (var summaryItem in summary)
{
probabilities.Add(summaryItem.Key, 1);
for (int i = 0; i < summaryItem.Value.Count; i++)
{
var item = summaryItem.Value[i];
var testItemElement = testDataElement.Elements[i];
var prob = CalculateProbability(item, testItemElement);
if (!prob.Equals(0))
{
probabilities[summaryItem.Key] *= prob;
}
}
}
return(probabilities);
}