add tf.linalg.global_norm #857

Author: Oceania2018

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

@@ -51,6 +51,9 @@ public Tensor batch_matmul(Tensor x, Tensor y, bool adj_x = false, bool adj_y =
             public Tensor inv(Tensor input, bool adjoint = false, string name = null)
                 => ops.matrix_inverse(input, adjoint: adjoint, name: name);
 
+            public Tensor global_norm(Tensor[] t_list, string name = null)
+                => clip_ops.global_norm(t_list, name: name);
+
             public Tensor lstsq(Tensor matrix, Tensor rhs,
                 NDArray l2_regularizer = null, bool fast = true, string name = null)
                 => ops.matrix_solve_ls(matrix, rhs, l2_regularizer: l2_regularizer, fast: fast, name: name);

src/TensorFlowNET.Core/Operations/clip_ops.cs

@@ -14,6 +14,7 @@ You may obtain a copy of the License at
    limitations under the License.
 ******************************************************************************/
 
+using System.Linq;
 using static Tensorflow.Binding;
 
 namespace Tensorflow
@@ -36,5 +37,24 @@ public static Tensor clip_by_value<T1, T2>(Tensor t, T1 clip_value_min, T2 clip_
                 return t_max;
             });
         }
+
+        /// <summary>
+        /// Computes the global norm of multiple tensors.
+        /// </summary>
+        /// <param name="t_list"></param>
+        /// <param name="name"></param>
+        /// <returns></returns>
+        public static Tensor global_norm(Tensor[] t_list, string name = null)
+        {
+            return tf_with(ops.name_scope(name, "global_norm", t_list), delegate
+            {
+                var half_squared_norms = t_list.Select(v => nn_ops.l2_loss(v)).ToArray();
+                var half_squared_norm = math_ops.reduce_sum(array_ops.stack(half_squared_norms));
+                var norm = math_ops.sqrt(half_squared_norm * 
+                    constant_op.constant(2.0, dtype: half_squared_norm.dtype),
+                    name: "global_norm");
+                return norm;
+            });
+        }
     }
 }

src/TensorFlowNET.Keras/Engine/MetricsContainer.cs

@@ -75,11 +75,19 @@ Metric _get_metric_object(string metric, Tensor y_t, Tensor y_p)
                     metric_obj = keras.metrics.sparse_categorical_accuracy;
                 else
                     metric_obj = keras.metrics.categorical_accuracy;
+
+                metric = "accuracy";
             }
             else if(metric == "mean_absolute_error" || metric == "mae")
+            {
                 metric_obj = keras.metrics.mean_absolute_error;
+                metric = "mean_absolute_error";
+            }
             else if (metric == "mean_absolute_percentage_error" || metric == "mape")
+            {
                 metric_obj = keras.metrics.mean_absolute_percentage_error;
+                metric = "mean_absolute_percentage_error";
+            }
             else
                 throw new NotImplementedException("");
 

src/TensorFlowNET.Keras/Metrics/MeanMetricWrapper.cs

@@ -4,7 +4,6 @@ namespace Tensorflow.Keras.Metrics
 {
     public class MeanMetricWrapper : Mean
     {
-        string name;
         Func<Tensor, Tensor, Tensor> _fn = null;
 
         public MeanMetricWrapper(Func<Tensor, Tensor, Tensor> fn, string name, TF_DataType dtype = TF_DataType.TF_FLOAT)

test/TensorFlowNET.UnitTest/ManagedAPI/LinalgTest.cs

@@ -1,4 +1,5 @@
 using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Tensorflow;
 using static Tensorflow.Binding;
 
 namespace TensorFlowNET.UnitTest.ManagedAPI
@@ -54,5 +55,13 @@ public void Einsum()
             var e = tf.linalg.einsum("ij,jk->ik", (m0, m1));
             Assert.AreEqual(e.shape, (2, 5));
         }
+
+        [TestMethod]
+        public void GlobalNorm()
+        {
+            var t_list = new Tensors(tf.constant(new float[] { 1, 2, 3, 4 }), tf.constant(new float[] { 5, 6, 7, 8 }));
+            var norm = tf.linalg.global_norm(t_list);
+            Assert.AreEqual(norm.numpy(), 14.282857f);
+        }
     }
 }