public void TestInterpolationMethod_CubicSpline_BoundaryNatural() { double[] t = new double[] { -2.0, -1.0, 0.0, 1.0, 2.0 }; double[] x = new double[] { 1.0, 2.0, -1.0, 0.0, 1.0 }; IInterpolationMethod method = Interpolation.CreateNaturalCubicSpline(t, x); Assert.IsInstanceOfType(typeof(CubicSplineInterpolation), method, "Type"); for (int i = 0; i < t.Length; i++) { // verify the interpolated values exactly at the sample points. Assert.AreEqual(x[i], method.Interpolate(t[i]), "A Exact Point " + i.ToString()); } // Maple: "with(CurveFitting);" // Maple: "evalf(subs({x=-2.4},Spline([[-2,1],[-1,2],[0,-1],[1,0],[2,1]], x, degree=3, endpoints='natural')),20);" NumericAssert.AreAlmostEqual(.144000000000000000, method.Interpolate(-2.4), 1e-15, "A -2.4"); NumericAssert.AreAlmostEqual(1.7906428571428571429, method.Interpolate(-0.9), 1e-15, "A -0.9"); NumericAssert.AreAlmostEqual(.47321428571428571431, method.Interpolate(-0.5), 1e-15, "A -0.5"); NumericAssert.AreAlmostEqual(-.80992857142857142857, method.Interpolate(-0.1), 1e-15, "A -0.1"); NumericAssert.AreAlmostEqual(-1.1089285714285714286, method.Interpolate(0.1), 1e-15, "A 0.1"); NumericAssert.AreAlmostEqual(-1.0285714285714285714, method.Interpolate(0.4), 1e-15, "A 0.4"); NumericAssert.AreAlmostEqual(.30285714285714285716, method.Interpolate(1.2), 1e-15, "A 1.2"); NumericAssert.AreAlmostEqual(189, method.Interpolate(10.0), 1e-15, "A 10.0"); NumericAssert.AreAlmostEqual(677, method.Interpolate(-10.0), 1e-15, "A -10.0"); }
private List <Position> GetPoints(List <Position> points, int type) { try { List <Position> result = new List <Position>(); IInterpolationMethod method = null; List <double> xs = new List <double>(); List <double> ys = new List <double>(); if (type > 0) { for (int i = 0; i < points.Count; i++) { xs.Add(points[i].X); ys.Add(points[i].Z); } } if (type == 0) { result.AddRange(points); } else if (type == 1) { method = Interpolation.CreateNaturalCubicSpline(xs, ys); } else if (type == 2) { method = Interpolation.CreateAkimaCubicSpline(xs, ys); } if (method != null) { for (int i = 0; i < points.Count; i++) { Position p1 = points[i]; Position p2 = points[i + 1]; double x = (p1.X + p2.X) / 2; } } return(result); } catch (System.Exception ex) { Log.Error(hisTag, "GetPoints", "Exception:" + ex); return(null); } }
public void TestInterpolationMethod_CubicSpline_BoundaryNatural() { double[] t = new double[] { -2.0, -1.0, 0.0, 1.0, 2.0 }; double[] x = new double[] { 1.0, 2.0, -1.0, 0.0, 1.0 }; IInterpolationMethod method = Interpolation.CreateNaturalCubicSpline(t, x); Assert.That(method, Is.TypeOf(typeof(CubicSplineInterpolation)), "Type"); for (int i = 0; i < t.Length; i++) { // verify the interpolated values exactly at the sample points. Assert.That(method.Interpolate(t[i]), Is.EqualTo(x[i]), "A Exact Point " + i.ToString()); } // Maple: "with(CurveFitting);" // Maple: "evalf(subs({x=-2.4},Spline([[-2,1],[-1,2],[0,-1],[1,0],[2,1]], x, degree=3, endpoints='natural')),20);" Assert.That(method.Interpolate(-2.4), NumericIs.AlmostEqualTo(.144000000000000000, 1e-15), "A -2.4"); Assert.That(method.Interpolate(-0.9), NumericIs.AlmostEqualTo(1.7906428571428571429, 1e-15), "A -0.9"); Assert.That(method.Interpolate(-0.5), NumericIs.AlmostEqualTo(.47321428571428571431, 1e-15), "A -0.5"); Assert.That(method.Interpolate(-0.1), NumericIs.AlmostEqualTo(-.80992857142857142857, 1e-15), "A -0.1"); Assert.That(method.Interpolate(0.1), NumericIs.AlmostEqualTo(-1.1089285714285714286, 1e-15), "A 0.1"); Assert.That(method.Interpolate(0.4), NumericIs.AlmostEqualTo(-1.0285714285714285714, 1e-15), "A 0.4"); Assert.That(method.Interpolate(1.2), NumericIs.AlmostEqualTo(.30285714285714285716, 1e-15), "A 1.2"); Assert.That(method.Interpolate(10.0), NumericIs.AlmostEqualTo((double)189, 1e-15), "A 10.0"); Assert.That(method.Interpolate(-10.0), NumericIs.AlmostEqualTo((double)677, 1e-15), "A -10.0"); // Test Linear Case for (int k = 2; k < 6; k++) { double[] linx, liny, linxtest, linytest; BuildLinearCase(2, k + 1, out linx, out liny, out linxtest, out linytest); IInterpolationMethod linearMethod = Interpolation.CreateNaturalCubicSpline(linx, liny); for (int i = 0; i < linxtest.Length; i++) { Assert.That(linearMethod.Interpolate(linxtest[i]), NumericIs.AlmostEqualTo(linytest[i], 1e-12), String.Format("Linear k={0} i={1}", k, i)); } } }