* @param nData Number of data points
* @param degree
*/
private LeastSquaresRegressionResult regress(final DoubleMatrix2D xDataMatrix, final DoubleMatrix1D yDataVector, final int nData, final int degree) {
final Decomposition<QRDecompositionResult> qrComm = new QRDecompositionCommons();
final DecompositionResult decompResult = qrComm.evaluate(xDataMatrix);
_qrResult = (QRDecompositionResult) decompResult;
final DoubleMatrix2D qMatrix = _qrResult.getQ();
final DoubleMatrix2D rMatrix = _qrResult.getR();