feat: Add UpSampling1D layer and test.

src/TensorFlowNET.Core/Keras/ArgsDefinition/Reshaping/UpSampling2DArgs.cs

@@ -7,7 +7,7 @@ public class UpSampling2DArgs : AutoSerializeLayerArgs
         [JsonProperty("size")]
         public Shape Size { get; set; }
         [JsonProperty("data_format")]
-        public string DataFormat { get; set; }
+        public string DataFormat { get; set; } = "channels_last";
         /// <summary>
         /// 'nearest', 'bilinear'
         /// </summary>

src/TensorFlowNET.Core/Keras/ArgsDefinition/Reshaping/Upsampling1DArgs.cs

@@ -0,0 +1,10 @@
+using Newtonsoft.Json;
+
+namespace Tensorflow.Keras.ArgsDefinition
+{
+    public class UpSampling1DArgs : AutoSerializeLayerArgs
+    {
+        [JsonProperty("size")]
+        public int Size { get; set; }
+    }
+}

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

@@ -9,6 +9,10 @@ public partial interface ILayersApi
         public ILayer Reshape(Shape target_shape);
         public ILayer Reshape(object[] target_shape);
 
+        public ILayer UpSampling1D(
+            int size
+            );
+
         public ILayer UpSampling2D(Shape size = null,
                 string data_format = null,
                 string interpolation = "nearest");

src/TensorFlowNET.Keras/BackendImpl.cs

@@ -956,6 +956,32 @@ Tensors _step(Tensors tensors)
 
         }
 
+        /// <summary>
+        /// Repeats the elements of a tensor along an axis, like `np.repeat`.
+        /// </summary>
+        /// <param name="x"></param>
+        /// <param name="rep"></param>
+        /// <param name="axis"></param>
+        /// <returns></returns>
+        public Tensor repeat_elements(Tensor x, int rep, int axis)
+        {
+            var x_shape = x.shape.as_int_list();
+            if (x_shape[axis] != -1)
+            {
+                var splits = tf.split(x, x_shape[axis], axis:axis);
+                var x_rep = splits.SelectMany(s => Enumerable.Repeat(s, rep)).ToArray();
+                return concatenate(x_rep, axis);
+            }
+            //var auxiliary_axis = axis + 1;
+            //x_shape = x.shape;
+            //var x_rep = tf.expand_dims(x, auxiliary_axis);
+            //var reps = np.ones(x_shape.Length + 1);
+            //reps[auxiliary_axis] = rep;
+            //x_rep = tf.tile(x_rep, reps);
+
+            throw new NotImplementedException();
+
+        }
         public Tensor reverse(Tensor input, int axis)
         {
             return reverse(input, new int[] { axis });

src/TensorFlowNET.Keras/Layers/LayersApi.Reshaping.cs

@@ -6,35 +6,48 @@
 
 namespace Tensorflow.Keras.Layers {
       public partial class LayersApi {
-            /// <summary>
-            /// Zero-padding layer for 2D input (e.g. picture).
-            /// </summary>
-            /// <param name="padding"></param>
-            /// <returns></returns>
-            public ILayer ZeroPadding2D ( NDArray padding )
+
+        /// <summary>
+        /// Upsampling layer for 1D inputs. Repeats each temporal step `size` times along the time axis.
+        /// </summary>
+        /// <param name="size"></param>
+        /// <returns></returns>
+        public ILayer UpSampling1D(int size)
+          => new UpSampling1D(new UpSampling1DArgs
+          {
+              Size = size
+          });
+
+        /// <summary>
+        /// Zero-padding layer for 2D input (e.g. picture).
+        /// </summary>
+        /// <param name="padding"></param>
+        /// <returns></returns>
+        public ILayer ZeroPadding2D ( NDArray padding )
                 => new ZeroPadding2D(new ZeroPadding2DArgs {
                       Padding = padding
                 });
 
-            /// <summary>
-            /// Upsampling layer for 2D inputs.<br/>
-            /// Repeats the rows and columns of the data by size[0] and size[1] respectively.
-            /// </summary>
-            /// <param name="size"></param>
-            /// <param name="data_format"></param>
-            /// <param name="interpolation"></param>
-            /// <returns></returns>
-            public ILayer UpSampling2D ( Shape size = null,
-                string data_format = null,
-                string interpolation = "nearest" )
-                => new UpSampling2D(new UpSampling2DArgs {
-                      Size = size ?? (2, 2)
-                });
+        /// <summary>
+        /// Upsampling layer for 2D inputs.<br/>
+        /// Repeats the rows and columns of the data by size[0] and size[1] respectively.
+        /// </summary>
+        /// <param name="size"></param>
+        /// <param name="data_format"></param>
+        /// <param name="interpolation"></param>
+        /// <returns></returns>
+        public ILayer UpSampling2D(Shape size, string data_format, string interpolation)
+            => new UpSampling2D(new UpSampling2DArgs
+            {
+                Size = size,
+                DataFormat = data_format,
+                Interpolation = interpolation
+            });
 
-            /// <summary>
-            /// Permutes the dimensions of the input according to a given pattern.
-            /// </summary>
-            public ILayer Permute ( int[] dims )
+        /// <summary>
+        /// Permutes the dimensions of the input according to a given pattern.
+        /// </summary>
+        public ILayer Permute ( int[] dims )
                   => new Permute(new PermuteArgs {
                         dims = dims
                   });

src/TensorFlowNET.Keras/Layers/Reshaping/UpSampling1D.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using Tensorflow.Common.Types;
+using Tensorflow.Keras.ArgsDefinition;
+using Tensorflow.Keras.Engine;
+
+
+namespace Tensorflow.Keras.Layers
+{
+    /// <summary>
+    /// Upsampling layer for 1D inputs.
+    /// </summary>
+    public class UpSampling1D : Layer
+    {
+        UpSampling1DArgs args;
+        int size;
+
+        public UpSampling1D(UpSampling1DArgs args) : base(args)
+        {
+            this.args = args;
+            size = args.Size;
+            inputSpec = new InputSpec(ndim: 3);
+        }
+
+        protected override Tensors Call(Tensors inputs, Tensors state = null, bool? training = null, IOptionalArgs? optional_args = null)
+        {
+            var output = keras.backend.repeat_elements(inputs, size, axis: 1);
+            return output;
+        }
+    }
+}

src/TensorFlowNET.Keras/Layers/Reshaping/UpSampling2D.cs

@@ -10,6 +10,9 @@
 
 namespace Tensorflow.Keras.Layers
 {
+    /// <summary>
+    /// Upsampling layer for 2D inputs.
+    /// </summary>
     public class UpSampling2D : Layer
     {
         UpSampling2DArgs args;

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

@@ -1,4 +1,5 @@
 using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System;
 using Tensorflow.NumPy;
 using static Tensorflow.Binding;
 using static Tensorflow.KerasApi;
@@ -18,6 +19,15 @@ public void ZeroPadding2D()
             Assert.AreEqual((1, 2, 3, 2), y.shape);
         }
 
+        [TestMethod]
+        public void UpSampling1D()
+        {
+            Shape input_shape = (2, 2, 3);
+            var x = np.arange(input_shape.size).reshape(input_shape);
+            var y = tf.keras.layers.UpSampling1D(size: 2).Apply(x);
+            Assert.AreEqual((2, 4, 3), y.shape);
+        }
+
         [TestMethod]
         public void UpSampling2D()
         {