Accord.Statistics.Kernels.DynamicTimeWarping.Distance C# (CSharp) Method

DynamicTimeWarping Class Documentation Usage Examples Of Accord.Statistics.Kernels.DynamicTimeWarping::Distance Show file Open project: accord-net/framework

Distance() public method

Computes the squared distance in feature space between two points given in input space.

public Distance ( double x, double y ) : double
x	double	Vector x in input space.
y	double	Vector y in input space.
return	double

        public override double Distance(double[] x, double[] y)
        {
            if (x == y)
                return 0.0;

            double cos = k(x, y);

            if (degree == 1)
                return 2 - 2 * cos;

            return 2 - 2 * System.Math.Pow(cos, degree);
        }

Usage Example

Example #1

Show file

File: DynamicTimeWarpingTest.cs Project: RLaumeyer/framework

        public void DistanceTest()
        {
            var x = new double[] { 0, 4, 2, 1 };
            var y = new double[] { 3, 2, };

            DynamicTimeWarping target;
            double expected, actual;


            target = new DynamicTimeWarping(1);

            expected = 0;
            actual = target.Distance(x, x);
            Assert.AreEqual(expected, actual, 0);

            expected = 0;
            actual = target.Distance(y, y);
            Assert.AreEqual(expected, actual, 0);

            expected = 2.1533930274840158;
            actual = target.Distance(x, y);
            Assert.AreEqual(expected, actual);
            actual = target.Distance(y, x);
            Assert.AreEqual(expected, actual);


            target = new DynamicTimeWarping(2, 1.42);
            var z = new double[] { 3, 2, 1, 5, 7, 8 };

            expected = 0;
            actual = target.Distance(x, x);
            Assert.AreEqual(expected, actual);

            expected = 0;
            actual = target.Distance(y, y);
            Assert.AreEqual(expected, actual);

            expected = 0;
            actual = target.Distance(z, z);
            Assert.AreEqual(expected, actual);

            expected = 2.2180712512020921;
            actual = target.Distance(x, z);
            Assert.AreEqual(expected, actual);
            actual = target.Distance(z, x);
            Assert.AreEqual(expected, actual);

            expected = 1.1582243214162151;
            actual = target.Distance(x, y);
            Assert.AreEqual(expected, actual);
            actual = target.Distance(y, x);
            Assert.AreEqual(expected, actual);


            target = new DynamicTimeWarping(1, 0.0000000001);

            expected = 0;
            actual = target.Distance(x, x);
            Assert.AreEqual(expected, actual);

            expected = 0;
            actual = target.Distance(y, y);
            Assert.AreEqual(expected, actual);

            expected = 1.9999999999333331;
            actual = target.Distance(x, y);
            Assert.AreEqual(expected, actual);
            actual = target.Distance(y, x);
            Assert.AreEqual(expected, actual);



            target = new DynamicTimeWarping(1, 292.12);

            expected = 0;
            actual = target.Distance(x, x);
            Assert.AreEqual(expected, actual);
            actual = target.Distance(y, y);
            Assert.AreEqual(expected, actual);

            expected = 0.00029292648999024173;
            actual = target.Distance(x, y);
            Assert.AreEqual(expected, actual);
            actual = target.Distance(y, x);
            Assert.AreEqual(expected, actual);
        }

DynamicTimeWarping

Clone

Dispose

Distance

DynamicTimeWarping

Function

initialize

onDeserialized

snorm