// Calculate correlation between the two sets of values
public void Button1_Click(object sender, EventArgs e)
{
// (OS)
CorrelatorService service = new CorrelatorService();
List<OCMRawData> rawdata = service.getRawData(int.Parse(SourceDropDown.SelectedValue), CounterDropDown.SelectedValue, int.Parse(ServerDropDown.SelectedValue));
List<OCMRawData> rawdata2 = service.getRawData(int.Parse(SourceDropDown2.SelectedValue), CounterDropDown2.SelectedValue, int.Parse(ServerDropDown2.SelectedValue));
// (AM)
double[] array1 = colData(rawdata);
double[] array2 = colData(rawdata2);
// (AM & OS)
double[] arr = new double[rawdata.Count];
double[] arr2 = new double[rawdata2.Count];
// (The following (START-END) is taken from the following website: http://mantascode.com/c-how-to-get-correlation-coefficient-of-two-arrays/ )
// What is used to work out one- to- one correlation
double[] array_xy = new double[arr.Length];
double[] array_xp2 = new double[arr.Length];
double[] array_yp2 = new double[arr2.Length];
for (int i = 0; i < arr.Length; i++)
array_xy[i] = arr[i] * arr2[i];
for (int i = 0; i < arr.Length; i++)
array_xp2[i] = Math.Pow(arr[i], 2.0);
for (int i = 0; i < arr2.Length; i++)
array_yp2[i] = Math.Pow(arr2[i], 2.0);
double sum_x = 0;
double sum_y = 0;
foreach (double n in arr)
sum_x += n;
foreach (double n in arr2)
sum_y += n;
double sum_xy = 0;
foreach (double n in array_xy)
sum_xy += n;
double sum_xpow2 = 0;
foreach (double n in array_xp2)
sum_xpow2 += n;
double sum_ypow2 = 0;
foreach (double n in array_yp2)
sum_ypow2 += n;
double Ex2 = Math.Pow(sum_x, 2.00);
double Ey2 = Math.Pow(sum_y, 2.00);
// The actual correlation calculation
double Correl =
(arr.Length * sum_xy - sum_x * sum_y) /
Math.Sqrt((arr.Length * sum_xpow2 - Ex2) * (arr.Length * sum_ypow2 - Ey2));
// Display correlation coefficient of one to one
correlationtextbox.Text = ("CORREL : "+ Correl);
// Idea of correlation algorithm before searching online for help..
// (OS)
// strongcorrelation = false
// get 1st entity instance from user, store in variable
// get second entity instance from user, store in variable
// get counter from user, store in variable
// get total (t) value of each array
// while traversing through 1st array
//traverse through second.
// if 2nd array value is > x and 1st array value > x
// then increment by 1. increments stored in i
// then we can say if i > (0.75 x t), 3/4 being the threshold of a somewhat 'good' correlation
// calculate correlation, store value in variable
// strongcorrelation = true
}
// When server (entity) is changed the values in the 1st list box change
// (OS)
public void ServerDropDown_SelectedIndexChanged(object sender, EventArgs e)
{
CorrelatorService service = new CorrelatorService();
ResultsListBox.Items.Clear();
List<OCMRawData> rawdata = service.getRawData(int.Parse(SourceDropDown.SelectedValue), CounterDropDown.SelectedValue, int.Parse(ServerDropDown.SelectedValue));
//add items to 1st results list
foreach (OCMRawData rw in rawdata)
ResultsListBox.Items.Add(new ListItem(rw.value.ToString()));
}
