Examples: added NeuralNetXor

src/TensorFlowNET.Core/APIs/tf.math.cs

@@ -298,5 +298,8 @@ namespace Tensorflow
 
         public static Tensor argmax(Tensor input, int axis = -1, string name = null, int? dimension = null, TF_DataType output_type = TF_DataType.TF_INT64)
             => gen_math_ops.arg_max(input, axis, name: name, output_type: output_type);
+
+        public static Tensor square(Tensor x, string name = null)
+            => gen_math_ops.square(x, name: name);
     }
 }

src/TensorFlowNET.Core/APIs/tf.nn.cs

@@ -26,7 +26,9 @@ namespace Tensorflow
                     partition_strategy: partition_strategy,
                     name: name);
 
-            public static IActivation relu => new relu();
+            public static IActivation relu() => new relu();
+
+            public static Tensor relu(Tensor features, string name = null) => gen_nn_ops.relu(features, name);
 
             public static Tensor[] fused_batch_norm(Tensor x,
                 RefVariable scale,

src/TensorFlowNET.Core/APIs/tf.random.cs

@@ -29,5 +29,13 @@ namespace Tensorflow
             TF_DataType dtype = TF_DataType.TF_FLOAT,
             int? seed = null,
             string name = null) => random_ops.random_uniform(shape, minval, maxval, dtype, seed, name);
+
+        public static Tensor truncated_normal(int[] shape,
+            float mean = 0.0f,
+            float stddev = 1.0f,
+            TF_DataType dtype = TF_DataType.TF_FLOAT,
+            int? seed = null,
+            string name = null)
+            => random_ops.truncated_normal(shape, mean, stddev, dtype, seed, name);
     }
 }

src/TensorFlowNET.Core/Operations/NnOps/gen_nn_ops.cs

@@ -1,6 +1,8 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Text;
+using Tensorflow.Operations.Activation;
 
 namespace Tensorflow.Operations
 {
@@ -173,5 +175,59 @@ namespace Tensorflow.Operations
 
             return (_op.outputs[0], _op.outputs[1]);
         }
+
+        /// <summary>
+        /// Computes rectified linear: `max(features, 0)`.
+        /// </summary>
+        /// <param name="features">A `Tensor`. Must be one of the following types: `float32`, `float64`, `int32`, `uint8`, `int16`, `int8`, `int64`, `bfloat16`, `uint16`, `half`, `uint32`, `uint64`, `qint8`.</param>
+        /// <param name="name">A name for the operation (optional).</param>
+        /// <returns>A `Tensor`. Has the same type as `features`.</returns>
+        public static Tensor relu(Tensor features, string name = null)
+        {
+
+            //_ctx = _context._context
+            //if _ctx is not None and _ctx._eager_context.is_eager:
+            //  try:
+            //    _result = _pywrap_tensorflow.TFE_Py_FastPathExecute(
+            //      _ctx._context_handle, _ctx._eager_context.device_name, "Relu", name,
+            //      _ctx._post_execution_callbacks, features)
+            //    return _result
+            //  except _core._FallbackException:
+            //    try:
+            //      return relu_eager_fallback(
+            //          features, name=name, ctx=_ctx)
+            //    except _core._SymbolicException:
+            //      pass  # Add nodes to the TensorFlow graph.
+            //    except (TypeError, ValueError):
+            //      result = _dispatch.dispatch(
+            //            relu, features=features, name=name)
+            //      if result is not _dispatch.OpDispatcher.NOT_SUPPORTED:
+            //        return result
+            //      raise
+            //  except _core._NotOkStatusException as e:
+            //    if name is not None:
+            //      message = e.message + " name: " + name
+            //    else:
+            //      message = e.message
+            //    _six.raise_from(_core._status_to_exception(e.code, message), None)
+            //# Add nodes to the TensorFlow graph.
+            //try:
+            OpDefLibrary _op_def_lib = new OpDefLibrary();
+            var _op = _op_def_lib._apply_op_helper("Relu", name: name, args: new { features });
+            return _op.outputs[0];
+            //except (TypeError, ValueError):
+            //  result = _dispatch.dispatch(
+            //        relu, features=features, name=name)
+            //  if result is not _dispatch.OpDispatcher.NOT_SUPPORTED:
+            //    return result
+            //  raise
+            // var _result = _op.outputs.ToArray();
+            //_inputs_flat = _op.inputs
+            //_attrs = ("T", _op.get_attr("T"))
+            //_execute.record_gradient(
+            //    "Relu", _inputs_flat, _attrs, _result, name)
+            //_result, = _result
+            // return _result;
+        }
     }
 }

test/TensorFlowNET.Examples/NeuralNetXor.cs

@@ -0,0 +1,96 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using NumSharp;
+using Tensorflow;
+
+namespace TensorFlowNET.Examples
+{
+    /// <summary>
+    /// Simple vanilla neural net solving the famous XOR problem
+    /// https://github.com/amygdala/tensorflow-workshop/blob/master/workshop_sections/getting_started/xor/README.md
+    /// </summary>
+    public class NeuralNetXor : Python, IExample
+    {
+        public int Priority => 2;
+        public bool Enabled { get; set; } = true;
+        public string Name => "NN XOR";
+
+        public int num_steps = 5000;
+
+        private (Operation, Tensor, RefVariable) make_graph(Tensor features,Tensor labels, int num_hidden = 8)
+        {
+            var stddev = 1 / Math.Sqrt(2);
+            var hidden_weights = tf.Variable(tf.truncated_normal(new int []{2, num_hidden}, stddev: (float) stddev ));
+
+            // Shape [4, num_hidden]
+            var hidden_activations = tf.nn.relu(tf.matmul(features, hidden_weights));
+
+            var output_weights = tf.Variable(tf.truncated_normal(
+                new[] {num_hidden, 1},
+                stddev: (float) (1 / Math.Sqrt(num_hidden))
+            ));
+
+            // Shape [4, 1]
+            var logits = tf.matmul(hidden_activations, output_weights);
+
+            // Shape [4]
+            var predictions = tf.sigmoid(tf.squeeze(logits));
+            var loss = tf.reduce_mean(tf.square(predictions - tf.cast(labels, tf.float32)));
+
+            var gs = tf.Variable(0, trainable: false);
+            var train_op = tf.train.GradientDescentOptimizer(0.2f).minimize(loss, global_step: gs);
+
+            return (train_op, loss, gs);
+        }
+
+        public bool Run()
+        {
+
+            var graph = tf.Graph();
+
+            var init=with(graph.as_default(), g =>
+            {
+                var features = tf.placeholder(tf.float32, new TensorShape(4, 2));
+                var labels = tf.placeholder(tf.int32, new TensorShape(4));
+
+                var (train_op, loss, gs) = make_graph(features, labels);
+                return tf.global_variables_initializer();
+            });
+
+            // Start tf session
+            with<Session>(tf.Session(), sess =>
+            {
+                init.run();
+                var step = 0;
+                var xy = np.array(new bool[,]
+                {
+                    {true, false, },
+                    {true, true, },
+                    {false, false, },
+                    {false, true, },
+                }, dtype: np.float32);
+
+                var y_ = np.array(new[] {true, false, false, true}, dtype: np.int32);
+                while (step < num_steps)
+                {
+                    // original python:
+                    //_, step, loss_value = sess.run(
+                    //          [train_op, gs, loss],
+                    //          feed_dict={features: xy, labels: y_}
+                    //      )
+                    // TODO: how the hell to port that to c#?
+                    //  var ( _, step, loss_value) = sess.run(new object[] {train_op, gs, loss},feed_dict: new {"features": xy, "labels": y_});
+                }
+                //tf.logging.info('Final loss is: {}'.format(loss_value))
+                //Console.WriteLine($"Final loss is: {loss_value}");
+
+            });
+            return true;
+        }
+
+        public void PrepareData()
+        {
+        }
+    }
+}

test/TensorFlowNET.Examples/TextClassification/cnn_models/VdCnn.cs

@@ -66,7 +66,7 @@ namespace TensorFlowNET.Examples.TextClassification
                     filters: num_filters[0],
                     kernel_size: new int[] { filter_sizes[0], embedding_size },
                     kernel_initializer: cnn_initializer,
-                    activation: tf.nn.relu);
+                    activation: tf.nn.relu());
 
                 conv0 = tf.transpose(conv0, new int[] { 0, 1, 3, 2 });
             });
@@ -99,12 +99,12 @@ namespace TensorFlowNET.Examples.TextClassification
             // ============= Fully Connected Layers =============
             with(tf.name_scope("fc-1"), scope =>
             {
-                fc1_out = tf.layers.dense(h_flat, 2048, activation: tf.nn.relu, kernel_initializer: fc_initializer);
+                fc1_out = tf.layers.dense(h_flat, 2048, activation: tf.nn.relu(), kernel_initializer: fc_initializer);
             });
 
             with(tf.name_scope("fc-2"), scope =>
             {
-                fc2_out = tf.layers.dense(fc1_out, 2048, activation: tf.nn.relu, kernel_initializer: fc_initializer);
+                fc2_out = tf.layers.dense(fc1_out, 2048, activation: tf.nn.relu(), kernel_initializer: fc_initializer);
             });
 
             with(tf.name_scope("fc-3"), scope =>
@@ -148,7 +148,7 @@ namespace TensorFlowNET.Examples.TextClassification
                         // batch normalization
                         conv = tf.layers.batch_normalization(conv, training: is_training);
                         // relu
-                        conv = tf.nn.relu.Activate(conv);
+                        conv = tf.nn.relu(conv);
                         conv = tf.transpose(conv, new int[] { 0, 1, 3, 2 });
                     });
                 }

test/TensorFlowNET.UnitTest/ExamplesTests/ExamplesTest.cs

@@ -108,6 +108,16 @@ namespace TensorFlowNET.ExamplesTests
             tf.Graph().as_default();
             new TextClassificationWithMovieReviews() { Enabled = true }.Run();
         }
+
+        [Ignore]
+        [TestMethod]
+        public void NeuralNetXor()
+        {
+            tf.Graph().as_default();
+            new NeuralNetXor() { Enabled = true }.Run();
+        }
+
         
+
     }
 }