private void compute(double[][] samples, LeveneTestMethod method, double percent)
{
this.Method = method;
int N = 0, k = samples.Length;
// Compute group means
var means = new double[samples.Length];
switch (method)
{
case LeveneTestMethod.Mean:
for (int i = 0; i < means.Length; i++)
{
means[i] = samples[i].Mean();
}
break;
case LeveneTestMethod.Median:
for (int i = 0; i < means.Length; i++)
{
means[i] = samples[i].Median();
}
break;
case LeveneTestMethod.TruncatedMean:
for (int i = 0; i < means.Length; i++)
{
means[i] = samples[i].TruncatedMean(percent);
}
break;
}
// Compute absolute centered samples
var z = new double[samples.Length][];
for (int i = 0; i < z.Length; i++)
{
z[i] = new double[samples[i].Length];
for (int j = 0; j < z[i].Length; j++)
{
z[i][j] = Math.Abs(samples[i][j] - means[i]);
}
}
// Compute means for the centered samples
var newMeans = new double[samples.Length];
for (int i = 0; i < newMeans.Length; i++)
{
newMeans[i] = z[i].Mean();
}
// Compute total mean
double totalMean = 0;
for (int i = 0; i < samples.Length; i++)
{
for (int j = 0; j < samples[i].Length; j++)
{
totalMean += z[i][j];
}
N += samples[i].Length;
}
totalMean /= N;
double sum1 = 0; // Numerator sum
for (int i = 0; i < samples.Length; i++)
{
int n = samples[i].Length;
double u = (newMeans[i] - totalMean);
sum1 += n * u * u;
}
double sum2 = 0; // Denominator sum
for (int i = 0; i < samples.Length; i++)
{
for (int j = 0; j < samples[i].Length; j++)
{
double u = z[i][j] - newMeans[i];
sum2 += u * u;
}
}
double num = (N - k) * sum1;
double den = (k - 1) * sum2;
double W = num / den;
int degree1 = k - 1;
int degree2 = N - k;
Compute(W, degree1, degree2, TwoSampleHypothesis.FirstValueIsGreaterThanSecond);
}
private void compute(double[][] samples, LeveneTestMethod method, double percent)
{
this.Method = method;
int N = 0, k = samples.Length;
// Compute group means
var means = new double[samples.Length];
switch (method)
{
case LeveneTestMethod.Mean:
for (int i = 0; i < means.Length; i++)
means[i] = Accord.Statistics.Tools.Mean(samples[i]);
break;
case LeveneTestMethod.Median:
for (int i = 0; i < means.Length; i++)
means[i] = Accord.Statistics.Tools.Median(samples[i]);
break;
case LeveneTestMethod.TruncatedMean:
for (int i = 0; i < means.Length; i++)
means[i] = Accord.Statistics.Tools.TruncatedMean(samples[i], percent);
break;
}
// Compute absolute centered samples
var z = new double[samples.Length][];
for (int i = 0; i < z.Length; i++)
{
z[i] = new double[samples[i].Length];
for (int j = 0; j < z[i].Length; j++)
z[i][j] = Math.Abs(samples[i][j] - means[i]);
}
// Compute means for the centered samples
var newMeans = new double[samples.Length];
for (int i = 0; i < newMeans.Length; i++)
newMeans[i] = Accord.Statistics.Tools.Mean(z[i]);
// Compute total mean
double totalMean = 0;
for (int i = 0; i < samples.Length; i++)
{
for (int j = 0; j < samples[i].Length; j++)
totalMean += z[i][j];
N += samples[i].Length;
}
totalMean /= N;
double sum1 = 0; // Numerator sum
for (int i = 0; i < samples.Length; i++)
{
int n = samples[i].Length;
double u = (newMeans[i] - totalMean);
sum1 += n * u * u;
}
double sum2 = 0; // Denominator sum
for (int i = 0; i < samples.Length; i++)
{
for (int j = 0; j < samples[i].Length; j++)
{
double u = z[i][j] - newMeans[i];
sum2 += u * u;
}
}
double num = (N - k) * sum1;
double den = (k - 1) * sum2;
double W = num / den;
int degree1 = k - 1;
int degree2 = N - k;
Compute(W, degree1, degree2, TwoSampleHypothesis.FirstValueIsGreaterThanSecond);
}