	@Test
	public void constantDataExtrapolatesConstantValues() {


		double[] data = createConstantDataArray();

		for (int degree = 0; degree < 3; ++degree) {
			LoessInterpolator loess = new LoessInterpolator.Builder().setWidth(7).setDegree(degree).interpolate(data);

			Double y = loess.smoothOnePoint(-100, 0, data.length - 1);
			assertNotNull(y);
			assertEquals("Bad value extrapolating left", data[0], y, 3.0e-9);

			y = loess.smoothOnePoint(1000.0, 0, data.length - 1);
			assertNotNull(y);
			assertEquals("Bad value extrapolating right", data[0], y, 3.0e-9);
		}
	}