Merge branch 'zoq-ann_model'

HISTORY.md

@@ -1,5 +1,6 @@
 ### mlpack ?.?.?
 ###### ????-??-??
+  * Add Model() to the FFN class to access individual layers (#2043).
 
 ### mlpack 3.2.1
 ###### 2019-10-01

src/mlpack/methods/ann/ffn.hpp

@@ -257,6 +257,14 @@ class FFN
    */
   void Add(LayerTypes<CustomLayers...> layer) { network.push_back(layer); }
 
+  //! Get the network model.
+  const std::vector<LayerTypes<CustomLayers...> >& Model() const
+  {
+    return network;
+  }
+  //! Modify the network model.
+  std::vector<LayerTypes<CustomLayers...> >& Model() { return network; }
+
   //! Return the number of separable functions (the number of predictor points).
   size_t NumFunctions() const { return numFunctions; }
 

src/mlpack/tests/feedforward_network_test.cpp

@@ -575,4 +575,41 @@ BOOST_AUTO_TEST_CASE(FFNTrainReturnObjective)
 
   BOOST_REQUIRE_EQUAL(std::isfinite(objVal), true);
 }
+
+/**
+ * Test that FFN::Model() allows us to access the instantiated network.
+ */
+BOOST_AUTO_TEST_CASE(FFNReturnModel)
+{
+  // Create dummy network.
+  FFN<NegativeLogLikelihood<> > model;
+  Linear<>* linearA = new Linear<>(3, 3);
+  model.Add(linearA);
+  Linear<>* linearB = new Linear<>(3, 4);
+  model.Add(linearB);
+
+  // Initialize network parameter.
+  model.ResetParameters();
+
+  // Set all network parameter to one.
+  model.Parameters().ones();
+
+  // Zero the second layer parameter.
+  linearB->Parameters().zeros();
+
+  // Get the layer parameter from layer A and layer B and store them in
+  // parameterA and parameterB.
+  arma::mat parameterA, parameterB;
+  boost::apply_visitor(ParametersVisitor(std::move(parameterA)),
+      model.Model()[0]);
+  boost::apply_visitor(ParametersVisitor(std::move(parameterB)),
+      model.Model()[1]);
+
+  CheckMatrices(parameterA, arma::ones(3 * 3 + 3, 1));
+  CheckMatrices(parameterB, arma::zeros(3 * 4 + 4, 1));
+
+  CheckMatrices(linearA->Parameters(), arma::ones(3 * 3 + 3, 1));
+  CheckMatrices(linearB->Parameters(), arma::zeros(3 * 4 + 4, 1));
+}
+
 BOOST_AUTO_TEST_SUITE_END();