Beispiel #1
0
        public void ARange()
        {
            var np = new NDArray <int>();

            np.ARange(3);

            Assert.IsTrue(np.ToString().Equals("array([0, 1, 2])"));

            np.ARange(7, 3);
            Assert.IsTrue(np.ToString().Equals("array([3, 4, 5, 6])"));

            np.ARange(7, 3, 2);
            Assert.IsTrue(np.ToString().Equals("array([3, 5])"));
        }
        public void ReShape()
        {
            var np  = new NDArray <int>();
            var np2 = np.ARange(6).ReShape(3, 2);

            Assert.IsTrue(np2.ToString().Equals("array([[0, 1], [2, 3], [4, 5]])"));
        }
        public void ReshapeNegative()
        {
            var np = new NDArray <int>();

            np.ARange(12);
            np.ReShape(-1, 2);
            Assert.IsTrue(np.Shape[0] == 6);
            Assert.IsTrue(np.Shape[1] == 2);

            np.ARange(12);
            np.ReShape(2, -1);
            Assert.IsTrue(np.Shape[0] == 2);
            Assert.IsTrue(np.Shape[1] == 6);

            np.ARange(12);
            np.ReShape(1, 3, 4);
            np.ReShape(-1, 3);
            Assert.IsTrue(np.Shape[0] == 4);
            Assert.IsTrue(np.Shape[1] == 3);

            np.ARange(12);
            np.ReShape(1, 3, 4);
            np.ReShape(3, -1);
            Assert.IsTrue(np.Shape[0] == 3);
            Assert.IsTrue(np.Shape[1] == 4);

            np.ARange(100 * 100 * 3);
            np.ReShape(100, 100, 3);
            np.ReShape(-1, 3);
            Assert.IsTrue(np.Shape[0] == 10000);
            Assert.IsTrue(np.Shape[1] == 3);

            np.ARange(15801033);
            np.ReShape(2531, 2081, 3);
            np.ReShape(-1, 3);
            Assert.IsTrue(np.Shape[0] == 5267011);
            Assert.IsTrue(np.Shape[1] == 3);
        }
        public void SeedsClassificationTest()
        {
            var filename       = @"data/seeds_dataset.csv";
            var np             = new NDArray <int>();
            var n_hidden_nodes = 5;    // nodes in hidden layers
            var l_rate         = 0.6;  // learning rate
            var n_epochs       = 1000; // number of training epochs
            var n_folds        = 4;    // number of folds for cross-validation

            /* =================================
            *   Read data (X,y) and normalize X
            *  ================================= */
            Console.WriteLine($"Reading '{filename}'...");
            (var X, var y) = Utils.ReadCsv(filename); // read as matrix of floats and int
            // normalize
            X.Normalize();
            // extract shape of X
            (var N, var d) = X.Shape;

            var nClasses = y.Unique().Length;

            Console.WriteLine($"X.shape = {X.Shape}, y.shape = {y.Shape}");
            Console.WriteLine($"size = {X.Data.Count}, dimesion = {X.NDim}, number of classes = {nClasses}");
            Console.WriteLine($"hidden nodes = {n_hidden_nodes}, learning rate = {l_rate}, epochs = {n_epochs}");

            /* ===================================
            *  Create cross-validation folds
            *  These are a list of a list of indices for each fold
            *  =================================== */

            var idx_all   = np.ARange(N, 0);
            var idx_folds = Utils.CrossValFolds(N, 4);

            /* ===================================
            *  Train and evaluate the model on each fold
            *  =================================== */
            // List<acc_train, acc_test = list(), list()  # training/test accuracy score
            Console.WriteLine("Training and cross-validating...");

            List <double> acc_train = new List <double>();
            List <double> acc_test  = new List <double>();

            for (int i = 0; i < n_folds; i++)
            {
                // Collect training and test data from folds
                var idx_test  = idx_folds[i];
                var idx_train = idx_all.Delete(idx_test);
                var X_train   = X[idx_train];
                var y_train   = y[idx_train];
                var X_test    = X[idx_test];
                var y_test    = y[idx_test];

                // Build neural network classifier model and train
                NetworkModel model = new NetworkModel();

                model.Layers.Add(new NeuralLayer(d, "INPUT"));
                model.Layers.Add(new NeuralLayer(n_hidden_nodes, "HIDDEN"));
                model.Layers.Add(new NeuralLayer(nClasses, "OUTPUT"));

                model.Build();

                model.Train(X_train, y_train, iterations: n_epochs, learningRate: l_rate);

                // Make predictions for training and test data
                var y_train_predict = model.Predict(X_train);
                var y_test_predict  = model.Predict(X_test);

                acc_train.Add(100 * y_train.Sum(y_train_predict) / y_train.Length);
                acc_test.Add(100 * y_test.Sum(y_test_predict) / y_test.Length);

                Console.WriteLine($"Fold {i + 1}/{n_folds}: train acc = {acc_train.Last()}%, test acc = {acc_test.Last()}% (n_train = {X_train.Length}, n_test = {X_test.Length})");
            }

            Console.WriteLine($"Avg train acc = {acc_train.Average()}%, avg test acc = {acc_test.Average()}%");
        }