public void RegressionStackingEnsembleLearner_CreateMetaFeatures_Then_Learn()
        {
            var learners = new IIndexedLearner <double>[]
            {
                new RegressionDecisionTreeLearner(2),
                new RegressionDecisionTreeLearner(5),
                new RegressionDecisionTreeLearner(7),
                new RegressionDecisionTreeLearner(9)
            };

            var sut = new RegressionStackingEnsembleLearner(learners, new RegressionDecisionTreeLearner(9),
                                                            new RandomCrossValidation <double>(5, 23), false);

            var(observations, targets) = DataSetUtilities.LoadDecisionTreeDataSet();

            var metaObservations = sut.LearnMetaFeatures(observations, targets);
            var model            = sut.LearnStackingModel(observations, metaObservations, targets);

            var predictions = model.Predict(observations);

            var evaluator = new MeanSquaredErrorRegressionMetric();
            var actual    = evaluator.Error(targets, predictions);

            Assert.AreEqual(0.06951934687172627, actual, 0.0001);
        }
Example #2
0
        public void RegressionStackingEnsembleLearner_CreateMetaFeatures_Then_Learn()
        {
            var learners = new IIndexedLearner <double>[]
            {
                new RegressionDecisionTreeLearner(2),
                new RegressionDecisionTreeLearner(5),
                new RegressionDecisionTreeLearner(7),
                new RegressionDecisionTreeLearner(9)
            };

            var sut = new RegressionStackingEnsembleLearner(learners, new RegressionDecisionTreeLearner(9),
                                                            new RandomCrossValidation <double>(5, 23), false);

            var parser       = new CsvParser(() => new StringReader(Resources.DecisionTreeData));
            var observations = parser.EnumerateRows("F1", "F2").ToF64Matrix();
            var targets      = parser.EnumerateRows("T").ToF64Vector();

            var metaObservations = sut.LearnMetaFeatures(observations, targets);
            var model            = sut.LearnStackingModel(observations, metaObservations, targets);

            var predictions = model.Predict(observations);

            var evaluator = new MeanSquaredErrorRegressionMetric();
            var actual    = evaluator.Error(targets, predictions);

            Assert.AreEqual(0.06951934687172627, actual, 0.0001);
        }