_ShapesFullySpecifiedAndEqual

src/TensorFlowNET.Core/Gradients/math_grad.cs

@@ -22,8 +22,10 @@ namespace Tensorflow.Gradients
             var sy = array_ops.shape(y);
             var (rx, ry) = gen_array_ops.broadcast_gradient_args(sx, sy);
 
-            var r1 = gen_array_ops.reshape(math_ops.reduce_sum(grad, rx), sx);
-            var r2 = gen_array_ops.reshape(math_ops.reduce_sum(grad, ry), sy);
+            var sum1 = math_ops.reduce_sum(grad, rx);
+            var r1 = gen_array_ops.reshape(sum1, sx);
+            var sum2 = math_ops.reduce_sum(grad, ry);
+            var r2 = gen_array_ops.reshape(sum2, sy);
 
             return new Tensor[] { r1, r2 };
         }
@@ -48,7 +50,8 @@ namespace Tensorflow.Gradients
             var x = op.inputs[0];
             var y = op.inputs[1];
             var grad = grads[0];
-            if (grad is Tensor && _ShapesFullySpecifiedAndEqual(x, y, grad) &&
+            if (grad is Tensor && 
+                _ShapesFullySpecifiedAndEqual(x, y, grad) &&
                 new TF_DataType[] { tf.int32, tf.float32 }.Contains(grad.dtype))
                 return new Tensor[] { gen_math_ops.mul(grad, y), gen_math_ops.mul(grad, x) };
 
@@ -60,10 +63,11 @@ namespace Tensorflow.Gradients
             y = math_ops.conj(y);
 
             var mul1 = gen_math_ops.mul(grad, y);
-            var mul2 = gen_math_ops.mul(x, grad);
             var reduce_sum1 = math_ops.reduce_sum(mul1, rx);
-            var reduce_sum2 = math_ops.reduce_sum(mul2, ry);
             var reshape1 = gen_array_ops.reshape(reduce_sum1, sx);
+
+            var mul2 = gen_math_ops.mul(x, grad);
+            var reduce_sum2 = math_ops.reduce_sum(mul2, ry);
             var reshape2 = gen_array_ops.reshape(reduce_sum2, sy);
 
             return new Tensor[] { reshape1, reshape2 };
@@ -146,7 +150,13 @@ namespace Tensorflow.Gradients
 
         public static bool _ShapesFullySpecifiedAndEqual(Tensor x, Tensor y, Tensor grad)
         {
-            return x.NDims == y.NDims && y.NDims == grad.NDims && x.NDims > -1;
+            var x_shape = x._shape_tuple();
+            var y_shape = y._shape_tuple();
+            var grad_shape = grad._shape_tuple();
+            return Enumerable.SequenceEqual(x_shape, y_shape) &&
+                Enumerable.SequenceEqual(y_shape, grad_shape) &&
+                x.NDims != -1 &&
+                !x_shape.Contains(-1);
         }
 
         public static Tensor[] _SumGrad(Operation op, Tensor[] grads)

src/TensorFlowNET.Core/Python.cs

@@ -2,6 +2,7 @@
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
+using System.Linq;
 using System.Text;
 
 namespace Tensorflow
@@ -16,6 +17,11 @@ namespace Tensorflow
             Console.WriteLine(obj.ToString());
         }
 
+        protected IEnumerable<int> range(int end)
+        {
+            return Enumerable.Range(0, end);
+        }
+
         public static T New<T>(object args) where T : IPyClass
         {
             var instance = Activator.CreateInstance<T>();

src/TensorFlowNET.Core/Tensors/Tensor.cs

@@ -43,6 +43,8 @@ namespace Tensorflow
         public IntPtr buffer => _handle == IntPtr.Zero ? IntPtr.Zero : c_api.TF_TensorData(_handle);
         public int num_consumers(TF_Output oper_out) => _handle == IntPtr.Zero ? 0 : c_api.TF_OperationOutputNumConsumers(oper_out);
 
+        private TF_Output? _tf_output;
+
         public long[] shape
         {
             get
@@ -123,7 +125,10 @@ namespace Tensorflow
 
         public TF_Output _as_tf_output()
         {
-            return new TF_Output(op, value_index);
+            if(!_tf_output.HasValue)
+                _tf_output = new TF_Output(op, value_index);
+
+            return _tf_output.Value;
         }
 
         public T[] Data<T>()

test/TensorFlowNET.Examples/LogisticRegression.cs

@@ -1,6 +1,8 @@
-using NumSharp.Core;
+using Newtonsoft.Json;
+using NumSharp.Core;
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Text;
 using Tensorflow;
 using TensorFlowNET.Examples.Utility;
@@ -26,8 +28,6 @@ namespace TensorFlowNET.Examples
 
         private void PrepareData()
         {
-           //var mnist = MnistDataSet.read_data_sets("logistic_regression", one_hot: true);
-
             // tf Graph Input
             var x = tf.placeholder(tf.float32, new TensorShape(-1, 784)); // mnist data image of shape 28*28=784
             var y = tf.placeholder(tf.float32, new TensorShape(-1, 10)); // 0-9 digits recognition => 10 classes
@@ -49,13 +49,37 @@ namespace TensorFlowNET.Examples
             // Gradient Descent
             var optimizer = tf.train.GradientDescentOptimizer(learning_rate).minimize(cost);
 
+            //var new_saver = tf.train.import_meta_graph("logistic_regression.meta.bin");
+
+            /*var text = JsonConvert.SerializeObject(tf.get_default_graph(), new JsonSerializerSettings
+            {
+                Formatting = Formatting.Indented
+            });*/
+
             // Initialize the variables (i.e. assign their default value)
             var init = tf.global_variables_initializer();
 
             with(tf.Session(), sess =>
             {
+                var mnist = MnistDataSet.read_data_sets("logistic_regression", one_hot: true);
                 // Run the initializer
                 sess.run(init);
+
+                // Training cycle
+                foreach(var epoch in range(training_epochs))
+                {
+                    var avg_cost = 0.0f;
+                    var total_batch = (int)(mnist.train.num_examples / batch_size);
+                    // Loop over all batches
+                    foreach (var i in range(total_batch))
+                    {
+                        var (batch_xs, batch_ys) = mnist.train.next_batch(batch_size);
+                        // Run optimization op (backprop) and cost op (to get loss value)
+                        /*sess.run(optimizer,
+                            new FeedItem(x, batch_xs),
+                            new FeedItem(y, batch_ys));*/
+                    }
+                }
             });
         }
     }

test/TensorFlowNET.Examples/Utility/DataSet.cs

@@ -9,10 +9,15 @@ namespace TensorFlowNET.Examples.Utility
     public class DataSet
     {
         private int _num_examples;
+        public int num_examples => _num_examples;
         private int _epochs_completed;
+        public int epochs_completed => _epochs_completed;
         private int _index_in_epoch;
+        public int index_in_epoch => _index_in_epoch;
         private NDArray _images;
+        public NDArray images => _images;
         private NDArray _labels;
+        public NDArray labels => _labels;
 
         public DataSet(NDArray images, NDArray labels, TF_DataType dtype, bool reshape)
         {
@@ -26,5 +31,33 @@ namespace TensorFlowNET.Examples.Utility
             _epochs_completed = 0;
             _index_in_epoch = 0;
         }
+
+        public (int, int) next_batch(int batch_size, bool fake_data = false, bool shuffle = true)
+        {
+            var start = _index_in_epoch;
+            // Shuffle for the first epoch
+            if(_epochs_completed == 0 && start == 0 && shuffle)
+            {
+                var perm0 = np.arange(_num_examples);
+                np.random.shuffle(perm0);
+                _images = images[perm0];
+                _labels = labels[perm0];
+            }
+
+            // Go to the next epoch
+            if (start + batch_size > _num_examples)
+            {
+                // Finished epoch
+                _epochs_completed += 1;
+
+                throw new NotImplementedException("next_batch");
+            }
+            else
+            {
+                _index_in_epoch += batch_size;
+                var end = _index_in_epoch;
+                return (_images[np.arange(start, end)], _labels[np.arange(start, end)]);
+            }
+        }
     }
 }