// Compute mean and covariance Matrix
CovarianceMatrix temp = CovarianceMatrix.make(relation);
Vector mean = temp.getMeanVector(relation).getColumnVector();
// debugFine(mean.toString());
Matrix covarianceMatrix = temp.destroyToNaiveMatrix();
// debugFine(covarianceMatrix.toString());
Matrix covarianceTransposed = covarianceMatrix.cheatToAvoidSingularity(SINGULARITY_CHEAT).inverse();
// Normalization factors for Gaussian PDF
final double fakt = (1.0 / (Math.sqrt(Math.pow(MathUtil.TWOPI, DatabaseUtil.dimensionality(relation)) * covarianceMatrix.det())));