migueldeicazaGH-118: Adding ReduceMean and related unit tests. (migueldeicaza#126)

cesarsouza · migueldeicaza · commit 6ba299eea1f6 · 2017-09-03T21:16:01.000-04:00
diff --git a/TensorFlowSharp/OperationsExtras.cs b/TensorFlowSharp/OperationsExtras.cs
@@ -62,6 +62,32 @@ public TFOutput ReduceSum (TFOutput input, TFOutput? axis = null, bool? keep_dim
 			return Sum (input, this.ReduceDims (input, axis), keep_dims, operName);
 		}
 
+		/// <summary>
+		/// Computes the mean of elements across dimensions of a tensor.
+		/// </summary>
+		/// <returns>The reduced tensor.</returns>
+		/// <param name="input">The tensor to reduce. Should have numeric type.</param>
+		/// <param name="axis">The dimensions to reduce. If not set (the default), reduces all dimensions.</param>
+		/// <param name="keep_dims">If set to <c>true</c> retains reduced dimensions with length 1.</param>
+		/// <param name="operName">A name for the operation, optional.</param>
+		/// <remarks>
+		/// <para>
+		///   Reduces input_tensor along the dimensions given in axis.
+		/// Unless keep_dims is true, the rank of the tensor is reduced by 1 for each
+		/// entry in axis. If keep_dims is true, the reduced dimensions
+		/// are retained with length 1.</para>
+		/// 
+		/// <para>
+		/// If axis has no entries, all dimensions are reduced, and a
+		/// tensor with a single element is returned.</para>
+		/// </remarks>
+		public TFOutput ReduceMean (TFOutput input, TFOutput? axis = null, bool? keep_dims = false, string operName = null)
+		{
+			if (input.OutputType == TFDataType.Bool)
+				input = this.Cast (input, TFDataType.Int8);
+			return this.Mean (input, this.ReduceDims (input, axis), keep_dims, operName);
+		}
+
 		/// <summary>
 		/// Variable node, with a starting initial value.
 		/// </summary>
diff --git a/tests/TensorFlowSharp.Tests.CSharp/MathTests.cs b/tests/TensorFlowSharp.Tests.CSharp/MathTests.cs
@@ -0,0 +1,53 @@
+&#65279;using System.Collections.Generic;
+using TensorFlow;
+using Xunit;
+
+namespace TensorFlowSharp.Tests.CSharp
+{
+	public class MathTests
+	{
+		private static IEnumerable<object []> reduceMeanData ()
+		{
+			// Example from https://www.tensorflow.org/api_docs/python/tf/reduce_mean
+			// # 'x' is [[1., 1.]
+			// #         [2., 2.]]
+			//  tf.reduce_mean (x) ==> 1.5
+			//  tf.reduce_mean (x, 0) ==> [1.5, 1.5]
+			// 	tf.reduce_mean (x, 1) ==> [1., 2.]
+
+			var x = new double [,] { { 1, 1 },
+									 { 2, 2 } };
+
+			yield return new object [] { x, null, 1.5 };
+			yield return new object [] { x, 0, new double [] { 1.5, 1.5 } };
+			yield return new object [] { x, 1, new double [] { 1, 2 } };
+		}
+
+		[Theory]
+		[MemberData (nameof (reduceMeanData))]
+		public void Should_ReduceMean (double [,] input, int? axis, object expected)
+		{
+			using (var graph = new TFGraph ())
+			using (var session = new TFSession (graph)) {
+				var tinput = graph.Placeholder (TFDataType.Double, new TFShape (2, 2));
+
+				TFTensor [] result;
+				if (axis != null) {
+					var taxis = graph.Const (axis.Value);
+					TFOutput y = graph.ReduceMean (tinput, taxis);
+					result = session.Run (new [] { tinput, taxis }, new TFTensor [] { input, axis }, new [] { y });
+
+					double [] actual = (double [])result [0].GetValue ();
+					TestUtils.MatrixEqual (expected, actual, precision: 8);
+				} else {
+					TFOutput y = graph.ReduceMean (tinput, axis: null);
+					result = session.Run (new [] { tinput }, new TFTensor [] { input }, new [] { y });
+
+					double actual = (double)result [0].GetValue ();
+					TestUtils.MatrixEqual (expected, actual, precision: 8);
+				}
+			}
+		}
+
+	}
+}
diff --git a/tests/TensorFlowSharp.Tests.CSharp/TensorFlowSharp.Tests.CSharp.csproj b/tests/TensorFlowSharp.Tests.CSharp/TensorFlowSharp.Tests.CSharp.csproj
@@ -63,6 +63,7 @@
     <Compile Include="ArrayTests.cs" />
     <Compile Include="ClipTests.cs" />
     <Compile Include="BitwiseOperationTests.cs" />
+    <Compile Include="MathTests.cs" />
     <Compile Include="PartialRunTests.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="TestUtils.cs" />
diff --git a/tests/TensorFlowSharp.Tests.CSharp/TestUtils.cs b/tests/TensorFlowSharp.Tests.CSharp/TestUtils.cs
@@ -43,5 +43,22 @@ public static void MatrixEqual(Array expected, Array actual, int precision)
                     Assert.True(Object.Equals(ei.Current, ai.Current));
             }
         }
-    }
+
+		public static void MatrixEqual (object expected, object actual, int precision)
+		{
+			if (expected is Array) {
+				MatrixEqual (expected as Array, actual as Array, precision);
+				return;
+			}
+			var expectedType = expected.GetType ();
+
+			if (expectedType == typeof (double)) {
+				Assert.Equal ((double)expected, (double)actual, precision: precision);
+			} else if (expectedType == typeof (float)) {
+				Assert.Equal ((float)expected, (float)actual, precision: precision);
+			} else {
+				Assert.True (Object.Equals (expected, actual));
+			}
+		}
+	}
 }
