Пример #1
0
        public void Logistic_Regression_Test_CostFunction_1()
        {
            Matrix X = new[, ]
            {
                { 1, 1, 1 },
                { 1, 1, 1 },
                { 1, 1, 1 },
                { 8, 1, 6 },
                { 3, 5, 7 },
                { 4, 9, 2 }
            };

            Vector y     = new Vector(new double[] { 1, 0, 1, 0, 1, 0 });
            Vector theta = new Vector(new double[] { 0, 1, 0 });

            ICostFunction logisticCostFunction = new LogisticCostFunction()
            {
                X           = X,
                Y           = y,
                Lambda      = 3,
                Regularizer = new L2Regularizer()
            };

            double cost = logisticCostFunction.ComputeCost(theta.Copy());

            theta = logisticCostFunction.ComputeGradient(theta.Copy());

            Assert.Equal(2.2933d, System.Math.Round(cost, 4));

            Assert.Equal(1.6702d, System.Math.Round(theta[0], 4));
            Assert.Equal(2.1483d, System.Math.Round(theta[1], 4));
            Assert.Equal(1.0887d, System.Math.Round(theta[2], 4));
        }
Пример #2
0
        public void Logistic_Regression_Test_CostFunction_2_WithRegularization()
        {
            Matrix X = new[, ] {
                { 8, 1, 6 },
                { 3, 5, 7 },
                { 4, 9, 2 }
            };

            Vector y     = new Vector(new double[] { 1, 1, 0 });
            Vector theta = new Vector(new double[] { 0, 1, 0 });

            ICostFunction logisticCostFunction = new LogisticCostFunction()
            {
                X           = X,
                Y           = y,
                Lambda      = 3,
                Regularizer = new L2Regularizer()
            };

            double cost = logisticCostFunction.ComputeCost(theta.Copy());

            theta = logisticCostFunction.ComputeGradient(theta.Copy());

            Assert.Equal(3.6067d, System.Math.Round(cost, 4));

            Assert.Equal(0.6093d, System.Math.Round(theta[0], 4));
            Assert.Equal(3.8988d, System.Math.Round(theta[1], 4));
            Assert.Equal(0.1131d, System.Math.Round(theta[2], 4));
        }