Add new feature: add LSTMCell and test

src/TensorFlowNET.Core/Common/Types/GeneralizedTensorShape.cs

@@ -16,10 +16,6 @@ namespace Tensorflow.Common.Types
         {
             var elem = new TensorShapeConfig() { Items = new long?[] { dim } };
             Shapes = Enumerable.Repeat(elem, size).ToArray();
-            //Shapes = new TensorShapeConfig[size];
-            //Shapes.Initialize(new TensorShapeConfig() { Items = new long?[] { dim } });
-            //Array.Initialize(Shapes, new TensorShapeConfig() { Items = new long?[] { dim } });
-            ////Shapes = new TensorShapeConfig[] { new TensorShapeConfig() { Items = new long?[] { dim } } };
         }
 
         public GeneralizedTensorShape(Shape shape)

src/TensorFlowNET.Core/Keras/ArgsDefinition/Rnn/LSTMCellArgs.cs

@@ -1,7 +1,35 @@
-namespace Tensorflow.Keras.ArgsDefinition.Rnn
+using Newtonsoft.Json;
+using static Tensorflow.Binding; 
+
+namespace Tensorflow.Keras.ArgsDefinition.Rnn
 {
     // TODO: complete the implementation
-    public class LSTMCellArgs : LayerArgs
+    public class LSTMCellArgs : AutoSerializeLayerArgs
     {
+        [JsonProperty("units")]
+        public int Units { get; set; }
+        // TODO(Rinne): lack of initialized value of Activation. Merging keras
+        // into tf.net could resolve it.
+        [JsonProperty("activation")]
+        public Activation Activation { get; set; }
+        [JsonProperty("recurrent_activation")]
+        public Activation RecurrentActivation { get; set; }
+        [JsonProperty("use_bias")]
+        public bool UseBias { get; set; } = true;
+        [JsonProperty("dropout")]
+        public float Dropout { get; set; } = .0f;
+        [JsonProperty("recurrent_dropout")]
+        public float RecurrentDropout { get; set; } = .0f;
+        [JsonProperty("kernel_initializer")]
+        public IInitializer KernelInitializer { get; set; }
+        [JsonProperty("recurrent_initializer")]
+        public IInitializer RecurrentInitializer { get; set; }
+        [JsonProperty("bias_initializer")]
+        public IInitializer BiasInitializer { get; set; }
+        [JsonProperty("unit_forget_bias")]
+        public bool UnitForgetBias { get; set; } = true;
+        [JsonProperty("implementation")]
+        public int Implementation { get; set; } = 2;
+
     }
 }

src/TensorFlowNET.Core/Keras/ArgsDefinition/Rnn/SimpleRNNCellArgs.cs

@@ -1,7 +1,4 @@
 using Newtonsoft.Json;
-using System;
-using System.Collections.Generic;
-using System.Text;
 
 namespace Tensorflow.Keras.ArgsDefinition.Rnn
 {
@@ -25,5 +22,6 @@ namespace Tensorflow.Keras.ArgsDefinition.Rnn
         public IInitializer RecurrentInitializer { get; set; }
         [JsonProperty("bias_initializer")]
         public IInitializer BiasInitializer { get; set; }
+
     }
 }

src/TensorFlowNET.Core/Keras/Layers/ILayersApi.cs

@@ -160,6 +160,18 @@ namespace Tensorflow.Keras.Layers
         public ILayer Normalization(Shape? input_shape = null, int? axis = -1, float? mean = null, float? variance = null, bool invert = false);
         public ILayer LeakyReLU(float alpha = 0.3f);
 
+        public IRnnCell LSTMCell(int uints,
+            string activation = "tanh",
+            string recurrent_activation = "sigmoid",
+            bool use_bias = true,
+            string kernel_initializer = "glorot_uniform",
+            string recurrent_initializer = "orthogonal",
+            string bias_initializer = "zeros",
+            bool unit_forget_bias = true,
+            float dropout = 0f,
+            float recurrent_dropout = 0f,
+            int implementation = 2);
+
         public ILayer LSTM(int units,
             Activation activation = null,
             Activation recurrent_activation = null,

src/TensorFlowNET.Core/Operations/Initializers/Orthogonal.cs

@@ -58,8 +58,7 @@ public class Orthogonal : IInitializer
 
         if (num_rows < num_cols)
         {
-            // q = tf.linalg.matrix_transpose(q);
-            throw new NotImplementedException("");
+            q = array_ops.matrix_transpose(q);
         }
 
         return _gain * tf.reshape(q, shape);

src/TensorFlowNET.Core/Operations/array_ops.cs

@@ -947,6 +947,49 @@ namespace Tensorflow
             });
         }
 
+        /// <summary>
+        /// Transposes last two dimensions of tensor `a`.
+        /// For example:
+        /// <code> python
+        ///   x = tf.constant([[1, 2, 3], [4, 5, 6]])
+        ///   tf.matrix_transpose(x) # [[1, 4],
+        ///                         #  [2, 5],
+        ///                         #  [3, 6]]
+        /// </code>
+        /// Matrix with two batch dimensions.
+        /// x.shape is [1, 2, 3, 4]
+        /// tf.linalg.matrix_transpose(x) is shape [1, 2, 4, 3]
+        /// </summary>
+        /// <param name="a"></param>
+        /// <param name="name"></param>
+        /// <param name="conjugate"></param>
+        /// <returns></returns>
+        /// <exception cref="ValueError"></exception>
+        public static Tensor matrix_transpose(Tensor a, string name = "matrix_transpose", bool conjugate = false)
+        {
+            return tf_with(ops.name_scope(name, "transpose", new { a }), scope =>
+            {
+                var a_shape = a.shape;
+                var ndims = a.shape.ndim;
+                Axis perm;
+                if(ndims != 0)
+                {
+                    if (ndims < 2)
+                    {
+                        throw new ValueError("Argument `a` should be a (batch) matrix with rank " +
+                            $">= 2.  Received `a` = {a} with shape: {a_shape}");
+                    }
+                    perm = new Axis(Enumerable.Range(0, ndims - 2).Concat(new int[] { ndims - 1, ndims - 2 }).ToArray());
+                }
+                else
+                {
+                    var a_rank = a.rank;
+                    perm = new Axis(Enumerable.Range(0, a_rank - 2).Concat(new int[] { a_rank - 1, a_rank - 2 }).ToArray());
+                }
+                return transpose(a, perm:perm, conjugate:conjugate);
+            });
+        }
+
         public static Tensor[] split(Tensor value, Tensor size_splits, int axis, int num = -1,
             string name = "split")
         {

src/TensorFlowNET.Keras/Layers/LayersApi.cs

@@ -702,6 +702,7 @@ namespace Tensorflow.Keras.Layers
                 UseBias = use_bias,
                 KernelInitializer = GetInitializerByName(kernel_initializer),
                 RecurrentInitializer = GetInitializerByName(recurrent_initializer),
+                BiasInitializer = GetInitializerByName(bias_initializer),
                 Dropout = dropout,
                 RecurrentDropout = recurrent_dropout
             });
@@ -786,6 +787,33 @@ namespace Tensorflow.Keras.Layers
                 TimeMajor = time_major
             });
 
+
+        public IRnnCell LSTMCell(int uints,
+            string activation = "tanh",
+            string recurrent_activation = "sigmoid",
+            bool use_bias = true,
+            string kernel_initializer = "glorot_uniform",
+            string recurrent_initializer = "orthogonal", // TODO(Wanglongzhi2001),glorot_uniform has not been developed.
+            string bias_initializer = "zeros",
+            bool unit_forget_bias = true,
+            float dropout = 0f,
+            float recurrent_dropout = 0f,
+            int implementation = 2)
+            => new LSTMCell(new LSTMCellArgs
+            {
+                Units = uints,
+                Activation = keras.activations.GetActivationFromName(activation),
+                RecurrentActivation = keras.activations.GetActivationFromName(recurrent_activation),
+                UseBias = use_bias,
+                KernelInitializer = GetInitializerByName(kernel_initializer),
+                RecurrentInitializer = GetInitializerByName(recurrent_initializer),
+                BiasInitializer = GetInitializerByName(bias_initializer),
+                UnitForgetBias = unit_forget_bias,
+                Dropout = dropout,
+                RecurrentDropout = recurrent_dropout,
+                Implementation = implementation
+            });
+
         /// <summary>
         /// Long Short-Term Memory layer - Hochreiter 1997.
         /// </summary>

src/TensorFlowNET.Keras/Layers/Rnn/DropoutRNNCellMixin.cs

@@ -32,7 +32,7 @@ namespace Tensorflow.Keras.Layers.Rnn
 
         }
 
-        public Tensors? get_dropout_maskcell_for_cell(Tensors input, bool training, int count = 1)
+        public Tensors? get_dropout_mask_for_cell(Tensors input, bool training, int count = 1)
         {
             if (dropout == 0f)
                 return null;
@@ -44,7 +44,7 @@ namespace Tensorflow.Keras.Layers.Rnn
         }
 
         // Get the recurrent dropout mask for RNN cell.
-        public Tensors? get_recurrent_dropout_maskcell_for_cell(Tensors input, bool training, int count = 1)
+        public Tensors? get_recurrent_dropout_mask_for_cell(Tensors input, bool training, int count = 1)
         {
             if (dropout == 0f)
                 return null;

src/TensorFlowNET.Keras/Layers/Rnn/LSTMCell.cs

@@ -1,16 +1,240 @@
-using Tensorflow.Keras.ArgsDefinition.Rnn;
+using Serilog.Core;
+using System.Diagnostics;
+using Tensorflow.Common.Types;
+using Tensorflow.Keras.ArgsDefinition.Rnn;
 using Tensorflow.Keras.Engine;
+using Tensorflow.Keras.Saving;
+using Tensorflow.Keras.Utils;
 
 namespace Tensorflow.Keras.Layers.Rnn
 {
-    public class LSTMCell : Layer
+    /// <summary>
+    /// Cell class for the LSTM layer.
+    /// See [the Keras RNN API guide](https://www.tensorflow.org/guide/keras/rnn)
+    /// for details about the usage of RNN API.
+    /// This class processes one step within the whole time sequence input, whereas
+    /// `tf.keras.layer.LSTM` processes the whole sequence.
+    /// </summary>
+    public class LSTMCell : DropoutRNNCellMixin
     {
-        LSTMCellArgs args;
+        LSTMCellArgs _args;
+        IVariableV1 _kernel;
+        IVariableV1 _recurrent_kernel;
+        IInitializer _bias_initializer;
+        IVariableV1 _bias;
+        GeneralizedTensorShape _state_size;
+        GeneralizedTensorShape _output_size;
+        public override GeneralizedTensorShape StateSize => _state_size;
 
+        public override GeneralizedTensorShape OutputSize => _output_size;
+
+        public override bool IsTFRnnCell => true;
+
+        public override bool SupportOptionalArgs => false;
         public LSTMCell(LSTMCellArgs args)
             : base(args)
         {
-            this.args = args;
+            _args = args;
+            if (args.Units <= 0)
+            {
+                throw new ValueError(
+                            $"units must be a positive integer, got {args.Units}");
+            }
+            _args.Dropout = Math.Min(1f, Math.Max(0f, this._args.Dropout));
+            _args.RecurrentDropout = Math.Min(1f, Math.Max(0f, this._args.RecurrentDropout));
+            if (_args.RecurrentDropout != 0f && _args.Implementation != 1)
+            {
+                Debug.WriteLine("RNN `implementation=2` is not supported when `recurrent_dropout` is set." +
+                    "Using `implementation=1`.");
+                _args.Implementation = 1;
+            }
+
+            _state_size = new GeneralizedTensorShape(_args.Units, 2);
+            _output_size = new GeneralizedTensorShape(_args.Units);
+
+
+        }
+
+        public override void build(KerasShapesWrapper input_shape)
+        {
+            var single_shape = input_shape.ToSingleShape();
+            var input_dim = single_shape[-1];
+            _kernel = add_weight("kernel", (input_dim, _args.Units * 4),
+                initializer: _args.KernelInitializer
+            );
+
+            _recurrent_kernel = add_weight("recurrent_kernel", (_args.Units, _args.Units * 4),
+                initializer: _args.RecurrentInitializer
+            );
+
+            if (_args.UseBias)
+            {
+                if (_args.UnitForgetBias)
+                {
+                    Tensor bias_initializer()
+                    {
+                        return keras.backend.concatenate(
+                            new Tensors(
+                            _args.BiasInitializer.Apply(new InitializerArgs(shape: (_args.Units))),
+                            tf.ones_initializer.Apply(new InitializerArgs(shape: (_args.Units))),
+                            _args.BiasInitializer.Apply(new InitializerArgs(shape: (_args.Units)))), axis: 0);
+                    }
+                }
+                else
+                {
+                    _bias_initializer = _args.BiasInitializer;
+                }
+                _bias = add_weight("bias", (_args.Units * 4),
+                    initializer: _args.BiasInitializer);
+            }
+            built = true;
+        }
+        protected override Tensors Call(Tensors inputs, Tensors states = null, bool? training = null, IOptionalArgs? optional_args = null)
+        {
+            var h_tm1 = states[0]; // previous memory state
+            var c_tm1 = states[1]; // previous carry state
+
+            var dp_mask = get_dropout_mask_for_cell(inputs, training.Value, count: 4);
+            var rec_dp_mask = get_recurrent_dropout_mask_for_cell(
+                               h_tm1, training.Value, count: 4);
+
+
+            Tensor c;
+            Tensor o;
+            if (_args.Implementation == 1)
+            {
+                Tensor inputs_i;
+                Tensor inputs_f;
+                Tensor inputs_c;
+                Tensor inputs_o;
+                if (0f < _args.Dropout && _args.Dropout < 1f)
+                {
+                    inputs_i = inputs * dp_mask[0];
+                    inputs_f = inputs * dp_mask[1];
+                    inputs_c = inputs * dp_mask[2];
+                    inputs_o = inputs * dp_mask[3];
+                }
+                else
+                {
+                    inputs_i = inputs;
+                    inputs_f = inputs;
+                    inputs_c = inputs;
+                    inputs_o = inputs;
+                }
+                var k = tf.split(_kernel.AsTensor(), num_split: 4, axis: 1);
+                Tensor k_i = k[0], k_f = k[1], k_c = k[2], k_o = k[3];
+                var x_i = math_ops.matmul(inputs_i, k_i);
+                var x_f = math_ops.matmul(inputs_f, k_f);
+                var x_c = math_ops.matmul(inputs_c, k_c);
+                var x_o = math_ops.matmul(inputs_o, k_o);
+                if(_args.UseBias)
+                {
+                    var b = tf.split(_bias.AsTensor(), num_split: 4, axis: 0);
+                    Tensor b_i = b[0], b_f = b[1], b_c = b[2], b_o = b[3];
+                    x_i = gen_nn_ops.bias_add(x_i, b_i);
+                    x_f = gen_nn_ops.bias_add(x_f, b_f);
+                    x_c = gen_nn_ops.bias_add(x_c, b_c);
+                    x_o = gen_nn_ops.bias_add(x_o, b_o);
+                }
+
+                Tensor h_tm1_i;
+                Tensor h_tm1_f;
+                Tensor h_tm1_c;
+                Tensor h_tm1_o;
+                if (0f < _args.RecurrentDropout && _args.RecurrentDropout < 1f)
+                {
+                    h_tm1_i = h_tm1 * rec_dp_mask[0];
+                    h_tm1_f = h_tm1 * rec_dp_mask[1];
+                    h_tm1_c = h_tm1 * rec_dp_mask[2];
+                    h_tm1_o = h_tm1 * rec_dp_mask[3];
+                }
+                else
+                {
+                    h_tm1_i = h_tm1;
+                    h_tm1_f = h_tm1;
+                    h_tm1_c = h_tm1;
+                    h_tm1_o = h_tm1;
+                }
+                var x = new Tensor[] { x_i, x_f, x_c, x_o };
+                var h_tm1_array = new Tensor[] { h_tm1_i, h_tm1_f, h_tm1_c, h_tm1_o };
+                (c, o) = _compute_carry_and_output(x, h_tm1_array, c_tm1);
+            }
+            else
+            {
+                if (0f < _args.Dropout && _args.Dropout < 1f)
+                    inputs = inputs * dp_mask[0];
+                var z = math_ops.matmul(inputs, _kernel.AsTensor());
+                z += math_ops.matmul(h_tm1, _recurrent_kernel.AsTensor());
+                if (_args.UseBias)
+                {
+                    z = tf.nn.bias_add(z, _bias);
+                }
+                var z_array = tf.split(z, num_split: 4, axis: 1);
+                (c, o) = _compute_carry_and_output_fused(z_array, c_tm1);
+            }
+            var h = o * _args.Activation.Apply(c);
+            // 这里是因为 Tensors 类初始化的时候会把第一个元素之后的元素打包成一个数组
+            return new Tensors(h, h, c);
+        }
+
+        /// <summary>
+        /// Computes carry and output using split kernels.
+        /// </summary>
+        /// <param name="x"></param>
+        /// <param name="h_tm1"></param>
+        /// <param name="c_tm1"></param>
+        /// <returns></returns>
+        /// <exception cref="NotImplementedException"></exception>
+        public Tensors _compute_carry_and_output(Tensor[] x, Tensor[] h_tm1, Tensor c_tm1) 
+        {
+            Tensor x_i = x[0], x_f = x[1], x_c = x[2], x_o = x[3];
+            Tensor h_tm1_i = h_tm1[0], h_tm1_f = h_tm1[1], h_tm1_c = h_tm1[2], 
+                h_tm1_o = h_tm1[3];
+
+            var _recurrent_kernel_tensor = _recurrent_kernel.AsTensor();
+            var startIndex = _recurrent_kernel_tensor.shape[0];
+            var endIndex = _recurrent_kernel_tensor.shape[1];
+            var _recurrent_kernel_slice = tf.slice(_recurrent_kernel_tensor, 
+                new[] { 0, 0 }, new[] { startIndex, _args.Units });
+            var i = _args.RecurrentActivation.Apply(
+                    x_i + math_ops.matmul(h_tm1_i, _recurrent_kernel_slice));
+            _recurrent_kernel_slice = tf.slice(_recurrent_kernel_tensor,
+                new[] { 0, _args.Units }, new[] { startIndex, _args.Units * 2});
+            var f = _args.RecurrentActivation.Apply(
+                    x_f + math_ops.matmul(h_tm1_f, _recurrent_kernel_slice));
+            _recurrent_kernel_slice = tf.slice(_recurrent_kernel_tensor,
+                new[] { 0, _args.Units * 2 }, new[] { startIndex, _args.Units * 3 });
+            var c = f * c_tm1 + i * _args.Activation.Apply(
+                    x_c + math_ops.matmul(h_tm1_c, _recurrent_kernel_slice));
+            _recurrent_kernel_slice = tf.slice(_recurrent_kernel_tensor,
+                new[] { 0, _args.Units * 3 }, new[] { startIndex, endIndex });
+            var o = _args.RecurrentActivation.Apply(
+                x_o + math_ops.matmul(h_tm1_o, _recurrent_kernel_slice));
+
+            return new Tensors(c, o);
+        }
+
+        /// <summary>
+        /// Computes carry and output using fused kernels.
+        /// </summary>
+        /// <param name="z"></param>
+        /// <param name="c_tm1"></param>
+        /// <returns></returns>
+        public Tensors _compute_carry_and_output_fused(Tensor[] z, Tensor c_tm1)
+        {
+            Tensor z0 = z[0], z1 = z[1], z2 = z[2], z3 = z[3];
+            var i = _args.RecurrentActivation.Apply(z0);
+            var f = _args.RecurrentActivation.Apply(z1);
+            var c = f * c_tm1 + i * _args.RecurrentActivation.Apply(z2);
+            var o = _args.RecurrentActivation.Apply(z3);
+            return new Tensors(c, o);
+        }
+
+        public Tensors get_initial_state(Tensors inputs = null, long? batch_size = null, TF_DataType? dtype = null)
+        {
+            return RnnUtils.generate_zero_filled_state_for_cell(this, inputs, batch_size.Value, dtype.Value);
         }
     }
+
+    
 }

src/TensorFlowNET.Keras/Layers/Rnn/SimpleRNNCell.cs

@@ -74,8 +74,8 @@ namespace Tensorflow.Keras.Layers.Rnn
         {
             // TODO(Rinne): check if it will have multiple tensors when not nested.
             Tensors prev_output = Nest.IsNested(states) ? new Tensors(states[0]) : states;
-            var dp_mask = get_dropout_maskcell_for_cell(inputs, training.Value);
-            var rec_dp_mask = get_recurrent_dropout_maskcell_for_cell(prev_output, training.Value);
+            var dp_mask = get_dropout_mask_for_cell(inputs, training.Value);
+            var rec_dp_mask = get_recurrent_dropout_mask_for_cell(prev_output, training.Value);
 
             Tensor h;
             var ranks = inputs.rank;

test/TensorFlowNET.Keras.UnitTest/Layers/Rnn.Test.cs

@@ -21,21 +21,6 @@ namespace Tensorflow.Keras.UnitTest.Layers
         [TestMethod]
         public void SimpleRNNCell()
         {
-            //var cell = tf.keras.layers.SimpleRNNCell(64, dropout: 0.5f, recurrent_dropout: 0.5f);
-            //var h0 = new Tensors { tf.zeros(new Shape(4, 64)) };
-            //var x = tf.random.normal((4, 100));
-            //var (y, h1) = cell.Apply(inputs: x, states: h0);
-            //var h2 = h1;
-            //Assert.AreEqual((4, 64), y.shape);
-            //Assert.AreEqual((4, 64), h2[0].shape);
-
-            //var model = keras.Sequential(new List<ILayer>
-            //{
-            //  keras.layers.InputLayer(input_shape: (4,100)),
-            //  keras.layers.SimpleRNNCell(64)
-            //});
-            //model.summary();
-
             var cell = tf.keras.layers.SimpleRNNCell(64, dropout: 0.5f, recurrent_dropout: 0.5f);
             var h0 = new Tensors { tf.zeros(new Shape(4, 64)) };
             var x = tf.random.normal((4, 100));
@@ -59,6 +44,17 @@ namespace Tensorflow.Keras.UnitTest.Layers
             Assert.AreEqual((32, 4), state[0].shape);
         }
 
+        [TestMethod]
+        public void LSTMCell()
+        {
+            var inputs = tf.ones((2, 100));
+            var states = new Tensors { tf.zeros((2, 4)), tf.zeros((2, 4)) };
+            var rnn = tf.keras.layers.LSTMCell(4);
+            var (output, new_states) = rnn.Apply(inputs, states);
+            Assert.AreEqual((2, 4), output.shape);
+            Assert.AreEqual((2, 4), new_states[0].shape);
+        }
+
         [TestMethod]
         public void SimpleRNN()
         {
@@ -99,6 +95,28 @@ namespace Tensorflow.Keras.UnitTest.Layers
             Assert.AreEqual((32, 5), output.shape);
         }
 
+        [TestMethod]
+        public void RNNForLSTMCell()
+        {
+            var inputs = tf.ones((5, 10, 8));
+            var rnn = tf.keras.layers.RNN(tf.keras.layers.LSTMCell(4));
+            var output = rnn.Apply(inputs);
+            Console.WriteLine($"output: {output}");
+            Assert.AreEqual((5, 4), output.shape);
+        }
+
+        [TestMethod]
+        public void MyTest()
+        {
+            var a = tf.zeros((2, 3));
+            var b = tf.ones_like(a);
+            var c = tf.ones((3,4));
+
+            var d = new Tensors { a, b, c };
+            var (A, BC) = d;
+            Console.WriteLine($"A:{A}");
+            Console.WriteLine($"BC:{BC}");
+        }
 
     }
 }