random_init.hpp

Go to the documentation of this file.

#ifndef MLPACK_METHODS_ANN_INIT_RULES_RANDOM_INIT_HPP
#define MLPACK_METHODS_ANN_INIT_RULES_RANDOM_INIT_HPP

#include <mlpack/prereqs.hpp>

namespace mlpack {
namespace ann  {

class RandomInitialization
{
 public:
  RandomInitialization(const double lowerBound = -1,
                       const double upperBound = 1) :
      lowerBound(lowerBound), upperBound(upperBound) { }

  RandomInitialization(const double bound) :
      lowerBound(-std::abs(bound)), upperBound(std::abs(bound)) { }

  template<typename eT>
  void Initialize(arma::Mat<eT>& W, const size_t rows, const size_t cols)
  {
    if (W.is_empty())
      W.set_size(rows, cols);

    W.randu();
    W *= (upperBound - lowerBound);
    W += lowerBound;
  }

  template<typename eT>
  void Initialize(arma::Mat<eT>& W)
  {
    if (W.is_empty())
      Log::Fatal << "Cannot initialize an empty matrix." << std::endl;

    W.randu();
    W *= (upperBound - lowerBound);
    W += lowerBound;
  }

  template<typename eT>
  void Initialize(arma::Cube<eT>& W,
                  const size_t rows,
                  const size_t cols,
                  const size_t slices)
  {
    if (W.is_empty())
      W.set_size(rows, cols, slices);

    for (size_t i = 0; i < slices; ++i)
      Initialize(W.slice(i), rows, cols);
  }

  template<typename eT>
  void Initialize(arma::Cube<eT>& W)
  {
    if (W.is_empty())
      Log::Fatal << "Cannot initialize an empty cube." << std::endl;

    for (size_t i = 0; i < W.n_slices; ++i)
      Initialize(W.slice(i));
  }

 private:
  double lowerBound;

  double upperBound;
}; // class RandomInitialization

} // namespace ann
} // namespace mlpack

#endif