Accord.Tests.MachineLearning.C45LearningTest.new_method_create_tree C# (CSharp) Метод

        public void new_method_create_tree()
        {
            string[][] text = Resources.iris_data.Split(new[] { '\n' }, StringSplitOptions.RemoveEmptyEntries).Apply(x => x.Split(','));

            double[][] inputs = text.GetColumns(0, 1, 2, 3).To<double[][]>();

            string[] labels = text.GetColumn(4);

            var codebook = new Codification("Output", labels);
            int[] outputs = codebook.Translate("Output", labels);

            // And we can use the C4.5 for learning:
            var teacher = new C45Learning();

            // And finally induce the tree:
            var tree = teacher.Learn(inputs, outputs);

            // To get the estimated class labels, we can use
            int[] predicted = tree.Decide(inputs);

            // And the classification error can be computed as 
            double error = new ZeroOneLoss(outputs) // 0.0266
            {
                Mean = true
            }.Loss(tree.Decide(inputs));

            // Moreover, we may decide to convert our tree to a set of rules:
            DecisionSet rules = tree.ToRules();

            // And using the codebook, we can inspect the tree reasoning:
            string ruleText = rules.ToString(codebook, "Output",
                System.Globalization.CultureInfo.InvariantCulture);

            // The output is:
            string expected = @"Iris-setosa =: (2 <= 2.45)
Iris-versicolor =: (2 > 2.45) && (3 <= 1.75) && (0 <= 7.05) && (1 <= 2.85)
Iris-versicolor =: (2 > 2.45) && (3 <= 1.75) && (0 <= 7.05) && (1 > 2.85)
Iris-versicolor =: (2 > 2.45) && (3 > 1.75) && (0 <= 5.95) && (1 > 3.05)
Iris-virginica =: (2 > 2.45) && (3 <= 1.75) && (0 > 7.05)
Iris-virginica =: (2 > 2.45) && (3 > 1.75) && (0 > 5.95)
Iris-virginica =: (2 > 2.45) && (3 > 1.75) && (0 <= 5.95) && (1 <= 3.05)
";

            Assert.AreEqual(0.026666666666666668, error, 1e-10);

            double newError = ComputeError(rules, inputs, outputs);
            Assert.AreEqual(0.026666666666666668, newError, 1e-10);
            Assert.AreEqual(expected, ruleText);
        }