final double[][] xValues = new double[][] { {1., 2., 3., 4., 5., 6. }, {2., 2.1, 4., 5.1, 5.22, 6.8 } };
final double[][] yValues = new double[][] { {1., 1.1, 2., 3., 5.9, 6. }, {1., 2.1, 3., 3.1, 3.22, 4.8 } };
final int dim = xValues.length;
final int nData = xValues[0].length;
final int nKeys = 11 * nData;
final Interpolator1D[] interp = new Interpolator1D[] {new DoubleQuadraticInterpolator1D(), new ExponentialInterpolator1D(), new ISDAInterpolator1D(), new LinearInterpolator1D(),
new LogLinearInterpolator1D(), new NaturalCubicSplineInterpolator1D(), new PCHIPInterpolator1D(), new PCHIPYieldCurveInterpolator1D(),
new LogNaturalCubicMonotonicityPreservingInterpolator1D(), new StepInterpolator1D(), new StepUpperInterpolator1D(), new TimeSquareInterpolator1D() };
final int nMethods = interp.length;
for (int j = 0; j < dim; ++j) {
for (int i = 0; i < nMethods; ++i) {