add bias_set_visitor

src/mlpack/methods/ann/layer/atrous_convolution.hpp

@@ -165,6 +165,9 @@ class AtrousConvolution
   //! Modify the output height.
   size_t& OutputHeight() { return outputHeight; }
 
+  //! Modify the bias weights of the layer.
+  arma::mat& Bias() { return bias; }
+
   /**
    * Serialize the layer
    */

src/mlpack/methods/ann/layer/convolution.hpp

@@ -161,6 +161,9 @@ class Convolution
   //! Modify the output height.
   size_t& OutputHeight() { return outputHeight; }
 
+  //! Modify the bias weights of the layer.
+  arma::mat& Bias() { return bias; }
+
   /**
    * Serialize the layer
    */

src/mlpack/methods/ann/layer/layer_traits.hpp

@@ -112,6 +112,10 @@ HAS_MEM_FUNC(Loss, HasLoss);
 // can use with SFINAE to catch when a type has a Run() function.
 HAS_MEM_FUNC(Run, HasRunCheck);
 
+// This gives us a HasBiasCheck<T, U> type (where U is a function pointer) we
+// can use with SFINAE to catch when a type has a Bias() function.
+HAS_MEM_FUNC(Bias, HasBiasCheck);
+
 } // namespace ann
 } // namespace mlpack
 

src/mlpack/methods/ann/layer/linear.hpp

@@ -117,6 +117,9 @@ class Linear
   //! Modify the gradient.
   OutputDataType& Gradient() { return gradient; }
 
+  //! Modify the bias weights of the layer.
+  arma::mat& Bias() { return bias; }
+
   /**
    * Serialize the layer
    */

src/mlpack/methods/ann/layer/transposed_convolution.hpp

@@ -162,6 +162,9 @@ class TransposedConvolution
   //! Modify the output height.
   size_t& OutputHeight() { return outputHeight; }
 
+  //! Modify the bias weights of the layer.
+  arma::mat& Bias() { return bias; }
+
   /**
    * Serialize the layer
    */

src/mlpack/methods/ann/visitor/CMakeLists.txt

@@ -5,6 +5,8 @@ set(SOURCES
   add_visitor_impl.hpp
   backward_visitor.hpp
   backward_visitor_impl.hpp
+  bias_set_visitor.hpp
+  bias_set_visitor_impl.hpp
   copy_visitor.hpp
   copy_visitor_impl.hpp
   delete_visitor.hpp

src/mlpack/methods/ann/visitor/bias_set_visitor.hpp

@@ -0,0 +1,80 @@
+/**
+ * @file bias_set_visitor.hpp
+ * @author Toshal Agrawal
+ *
+ * This file provides an abstraction for the Bias() function for different
+ * layers and automatically directs any parameter to the right layer type.
+ *
+ * mlpack is free software; you may redistribute it and/or modify it under the
+ * terms of the 3-clause BSD license.  You should have received a copy of the
+ * 3-clause BSD license along with mlpack.  If not, see
+ * http://www.opensource.org/licenses/BSD-3-Clause for more information.
+ */
+#ifndef MLPACK_METHODS_ANN_VISITOR_BIAS_SET_VISITOR_HPP
+#define MLPACK_METHODS_ANN_VISITOR_BIAS_SET_VISITOR_HPP
+
+#include <mlpack/methods/ann/layer/layer_traits.hpp>
+
+#include <boost/variant.hpp>
+
+namespace mlpack {
+namespace ann {
+
+/**
+ * BiasSetVisitor update the module bias parameters given the parameters set.
+ */
+class BiasSetVisitor : public boost::static_visitor<size_t>
+{
+ public:
+  //! Update the bias parameters given the parameters set and offset.
+  BiasSetVisitor(arma::mat&& weight, const size_t offset = 0);
+
+  //! Update the parameters set.
+  template<typename LayerType>
+  size_t operator()(LayerType* layer) const;
+
+ private:
+  //! The parameters set.
+  arma::mat&& weight;
+
+  //! The parameters offset.
+  const size_t offset;
+
+  //! Do not update the bias parameters if the module doesn't implement the
+  //! Bias() or Model() function.
+  template<typename T>
+  typename std::enable_if<
+      !HasBiasCheck<T, arma::mat&(T::*)()>::value &&
+      !HasModelCheck<T>::value, size_t>::type
+  LayerSize(T* layer) const;
+
+  //! Update the bias parameters if the module implements the Model() function.
+  template<typename T>
+  typename std::enable_if<
+      !HasBiasCheck<T, arma::mat&(T::*)()>::value &&
+      HasModelCheck<T>::value, size_t>::type
+  LayerSize(T* layer) const;
+
+  //! Update the bias parameters if the module implements the Bias() function.
+  template<typename T>
+  typename std::enable_if<
+      HasBiasCheck<T, arma::mat&(T::*)()>::value &&
+      !HasModelCheck<T>::value, size_t>::type
+  LayerSize(T* layer) const;
+
+  //! Update the bias parameters if the module implements the Model() and
+  //! Bias() function.
+  template<typename T>
+  typename std::enable_if<
+      HasBiasCheck<T, arma::mat&(T::*)()>::value &&
+      HasModelCheck<T>::value, size_t>::type
+  LayerSize(T* layer) const;
+};
+
+} // namespace ann
+} // namespace mlpack
+
+// Include implementation.
+#include "bias_set_visitor_impl.hpp"
+
+#endif

src/mlpack/methods/ann/visitor/bias_set_visitor_impl.hpp

@@ -0,0 +1,94 @@
+/**
+ * @file bias_set_visitor_impl.hpp
+ * @author Toshal Agrawal
+ *
+ * Implementation of the Bias() function layer abstraction.
+ *
+ * mlpack is free software; you may redistribute it and/or modify it under the
+ * terms of the 3-clause BSD license.  You should have received a copy of the
+ * 3-clause BSD license along with mlpack.  If not, see
+ * http://www.opensource.org/licenses/BSD-3-Clause for more information.
+ */
+#ifndef MLPACK_METHODS_ANN_VISITOR_BIAS_SET_VISITOR_IMPL_HPP
+#define MLPACK_METHODS_ANN_VISITOR_BIAS_SET_VISITOR_IMPL_HPP
+
+// In case it hasn't been included yet.
+#include "bias_set_visitor.hpp"
+
+namespace mlpack {
+namespace ann {
+
+//! BiasSetVisitor visitor class.
+inline BiasSetVisitor::BiasSetVisitor(arma::mat&& weight, const size_t offset) :
+    weight(std::move(weight)),
+    offset(offset)
+{
+  /* Nothing to do here. */
+}
+
+template<typename LayerType>
+inline size_t BiasSetVisitor::operator()(LayerType* layer) const
+{
+  return LayerSize(layer);
+}
+
+template<typename T>
+inline typename std::enable_if<
+    !HasBiasCheck<T, arma::mat&(T::*)()>::value &&
+    !HasModelCheck<T>::value, size_t>::type
+BiasSetVisitor::LayerSize(T* /* layer */) const
+{
+  return 0;
+}
+
+template<typename T>
+inline typename std::enable_if<
+    !HasBiasCheck<T, arma::mat&(T::*)()>::value &&
+    HasModelCheck<T>::value, size_t>::type
+BiasSetVisitor::LayerSize(T* layer) const
+{
+  size_t modelOffset = 0;
+  for (size_t i = 0; i < layer->Model().size(); ++i)
+  {
+    modelOffset += boost::apply_visitor(BiasSetVisitor(
+        std::move(weight), modelOffset + offset), layer->Model()[i]);
+  }
+
+  return modelOffset;
+}
+
+template<typename T>
+inline typename std::enable_if<
+    HasBiasCheck<T, arma::mat&(T::*)()>::value &&
+    !HasModelCheck<T>::value, size_t>::type
+BiasSetVisitor::LayerSize(T* layer) const
+{
+  layer->Bias() = arma::mat(weight.memptr() + offset,
+      layer->Bias().n_rows, layer->Bias().n_cols, false, false);
+
+  return layer->Bias().n_elem;
+}
+
+template<typename T>
+inline typename std::enable_if<
+    HasBiasCheck<T, arma::mat&(T::*)()>::value &&
+    HasModelCheck<T>::value, size_t>::type
+BiasSetVisitor::LayerSize(T* layer) const
+{
+  layer->Bias() = arma::mat(weight.memptr() + offset,
+      layer->Bias().n_rows, layer->Bias().n_cols, false, false);
+
+  size_t modelOffset = layer->Bias().n_elem;
+  for (size_t i = 0; i < layer->Model().size(); ++i)
+  {
+    modelOffset += boost::apply_visitor(BiasSetVisitor(
+        std::move(weight), modelOffset + offset), layer->Model()[i]);
+  }
+
+  return modelOffset;
+}
+
+} // namespace ann
+} // namespace mlpack
+
+#endif