inverse_quadratic_function.hpp

Go to the documentation of this file.

 
#ifndef MLPACK_METHODS_ANN_ACTIVATION_FUNCTIONS_INVERSE_QUAD_FUNCTION_HPP
#define MLPACK_METHODS_ANN_ACTIVATION_FUNCTIONS_INVERSE_QUAD_FUNCTION_HPP
 
#include <mlpack/prereqs.hpp>
 
namespace mlpack {
namespace ann  {
 
class InvQuadFunction
{
 public:
  static double Fn(const double x)
  {
    return 1 / ( 1 + x * x);
  }
 
  template<typename InputVecType, typename OutputVecType>
  static void Fn(const InputVecType& x, OutputVecType& y)
  {
    y = 1 / (1 + arma::pow(x, 2));
  }
 
  static double Deriv(const double y)
  {
    return  - 2 * y / std::pow(1 + std::pow(y, 2), 2);
  }
 
  template<typename InputVecType, typename OutputVecType>
  static void Deriv(const InputVecType& x, OutputVecType& y)
  {
    y = - 2 * x / arma::pow(1 + arma::pow(x, 2), 2);
  }
}; // class InvQuadFunction
 
} // namespace ann
} // namespace mlpack
 
#endif