dynaml.tensorflow: Added Tanh activation function

Author: mandar2812

dynaml-core/src/main/scala-2.11/io/github/mandar2812/dynaml/tensorflow/layers/Tanh.scala

@@ -0,0 +1,33 @@
+/*
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+* */
+package io.github.mandar2812.dynaml.tensorflow.layers
+
+import org.platanios.tensorflow.api.learn.Mode
+import org.platanios.tensorflow.api.learn.layers.Activation
+import org.platanios.tensorflow.api.ops
+import org.platanios.tensorflow.api.ops.Output
+
+case class Tanh(override val name: String)
+  extends Activation(name) {
+  override val layerType: String = "Sigmoid"
+
+  override protected def _forward(input: Output, mode: Mode): Output = {
+    ops.Math.tanh(input)
+  }
+}

dynaml-core/src/main/scala-2.11/io/github/mandar2812/dynaml/tensorflow/package.scala

@@ -292,6 +292,8 @@ package object tensorflow {
     * */
   object dtflearn {
 
+    val Tanh: layers.Tanh.type  = layers.Tanh
+
     /**
       * Constructs a feed-forward layer.
       *