add CustomLayer

endymecy · endymecy · commit 585e63ce793a · 2017-07-01T11:08:36.000+08:00
diff --git a/dl4scala-examples/src/main/scala/org/dl4scala/examples/misc/customlayers/layer/CustomLayer.scala b/dl4scala-examples/src/main/scala/org/dl4scala/examples/misc/customlayers/layer/CustomLayer.scala
@@ -0,0 +1,84 @@
+package org.dl4scala.examples.misc.customlayers.layer
+
+import java.util
+
+import org.deeplearning4j.nn.conf.layers.{FeedForwardLayer, Layer}
+import CustomLayer.Builder
+import org.deeplearning4j.nn.api
+import org.deeplearning4j.nn.api.ParamInitializer
+import org.deeplearning4j.nn.conf.NeuralNetConfiguration
+import org.deeplearning4j.nn.params.DefaultParamInitializer
+import org.deeplearning4j.optimize.api.IterationListener
+import org.nd4j.linalg.activations.{Activation, IActivation}
+import org.nd4j.linalg.api.ndarray.INDArray
+/**
+  * Created by endy on 2017/7/1.
+  */
+class CustomLayer(builder: Builder) extends FeedForwardLayer(builder){
+  private var secondActivationFunction = builder.secondActivationFunction
+
+  def getSecondActivationFunction: IActivation =  secondActivationFunction
+
+  def setSecondActivationFunction(secondActivationFunction: IActivation): Unit = { //We also need setter/getter methods for our layer configuration fields (if any) for JSON serialization
+    this.secondActivationFunction = secondActivationFunction
+  }
+
+  override def instantiate(conf: NeuralNetConfiguration, iterationListeners: util.Collection[IterationListener],
+                           layerIndex: Int, layerParamsView: INDArray, initializeParams: Boolean): api.Layer = {
+    //The instantiate method is how we go from the configuration class (i.e., this class) to the implementation class
+
+    // (i.e., a CustomLayerImpl instance)
+    //For the most part, it's the same for each type of layer
+
+    val myCustomLayer = new CustomLayerImpl(conf)
+    myCustomLayer.setListeners(iterationListeners) //Set the iteration listeners, if any
+    myCustomLayer.setIndex(layerIndex) //Integer index of the layer
+
+    // Parameter view array: the network parameters for the entire network (all layers) are
+    // allocated in one big array. The relevant section of this parameter vector is extracted out for each layer,
+    // (i.e., it's a "view" array in that it's a subset of a larger array)
+    // This is a row vector, with length equal to the number of parameters in the layer
+    myCustomLayer.setParamsViewArray(layerParamsView)
+
+    // Initialize the layer parameters. For example,
+    // Note that the entries in paramTable (2 entries here: a weight array of shape [nIn,nOut] and biases of shape [1,nOut]
+    // are in turn a view of the 'layerParamsView' array.
+    val paramTable = initializer().init(conf, layerParamsView, initializeParams)
+    myCustomLayer.setParamTable(paramTable)
+    myCustomLayer.setConf(conf)
+    myCustomLayer
+  }
+
+  // This method returns the parameter initializer for this type of layer
+  // In this case, we can use the DefaultParamInitializer, which is the same one used for DenseLayer
+  // For more complex layers, you may need to implement a custom parameter initializer
+  override def initializer(): ParamInitializer = DefaultParamInitializer.getInstance
+}
+
+object CustomLayer {
+  class Builder extends FeedForwardLayer.Builder[Builder] {
+    var secondActivationFunction: IActivation = _
+
+    /**
+      * A custom property used in this custom layer example. See the CustomLayerExampleReadme.md for details
+      *
+      * @param secondActivationFunction Second activation function for the layer
+      */
+    def secondActivationFunction(secondActivationFunction: String): Builder =
+      secondActivationFunction1(Activation.fromString(secondActivationFunction))
+
+    /**
+      * A custom property used in this custom layer example. See the CustomLayerExampleReadme.md for details
+      *
+      * @param secondActivationFunction Second activation function for the layer
+      */
+    def secondActivationFunction1(secondActivationFunction: Activation): Builder = {
+      this.secondActivationFunction = secondActivationFunction.getActivationFunction
+      this
+    }
+
+    override def build[E <: Layer](): CustomLayer = {
+      new CustomLayer(this)
+    }
+  }
+}
