Accord.Statistics.Kernels.Sparse.SparseLinear.Distance C# (CSharp) Method

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 feature (kernel) space.
y double Vector y in feature (kernel) space.
return double
        public override double Distance(double[] x, double[] y)
        {
            if (x == y)
                return 0;

            return SquaredEuclidean(x, y);
        }

Usage Example

Example #1
0
        public void DistanceTest()
        {
            Linear dense = new Linear(1);
            SparseLinear target = new SparseLinear(1);

            double[] sx = { 1, -0.555556, 2, +0.250000, 3, -0.864407, 4, -0.916667 };
            double[] sy = { 1, -0.666667, 2, -0.166667, 3, -0.864407, 4, -0.916667 };
            double[] sz = { 1, -0.944444, 3, -0.898305, 4, -0.916667 };

            double[] dx = { -0.555556, +0.250000, -0.864407, -0.916667 };
            double[] dy = { -0.666667, -0.166667, -0.864407, -0.916667 };
            double[] dz = { -0.944444, +0.000000, -0.898305, -0.916667 };

            double expected, actual;

            expected = dense.Distance(dx, dy);
            actual = target.Distance(sx, sy);
            Assert.AreEqual(expected, actual);

            expected = dense.Distance(dx, dz);
            actual = target.Distance(sx, sz);
            Assert.AreEqual(expected, actual);

            expected = dense.Distance(dy, dz);
            actual = target.Distance(sy, sz);
            Assert.AreEqual(expected, actual);
        }