1e-14);
RealMatrix errors =
new Array2DRowRealMatrix(regression.estimateRegressionParametersVariance(), false);
final double[] s = { 1.0, -1.0 / 2.0, -1.0 / 3.0, -1.0 / 4.0, -1.0 / 5.0, -1.0 / 6.0 };
RealMatrix referenceVariance = new Array2DRowRealMatrix(s.length, s.length);
referenceVariance.walkInOptimizedOrder(new DefaultRealMatrixChangingVisitor() {
@Override
public double visit(int row, int column, double value)
throws MatrixVisitorException {
if (row == 0) {
return s[column];