@Test
public void quadraticDataReturnsDataOnParabolaWithQuadraticInterpolation() {

	double[] data = createQuadraticDataArray();
	LoessInterpolator loess = new LoessInterpolator.Builder().setWidth(500000).setDegree(2).interpolate(data);
	for (int i = -100; i < data.length + 100; ++i) {
		Double y = loess.smoothOnePoint(i, 0, data.length - 1);
		assertNotNull(y);
		assertEquals(String.format("Bad value at %d", i), 3.7 - 0.25 * i + 0.7 * i * i, y, 1.0e-10);
	}
}