ActivationFunction.h

//-------------------------------------------------------------------------------------------------------
// Copyright (C) Taylor Woll and panann contributors. All rights reserved.
// Licensed under the MIT license. See LICENSE.txt file in the project root for
// full license information.
//-------------------------------------------------------------------------------------------------------
 
#ifndef ACTIVATIONFUNCTION_H__
#define ACTIVATIONFUNCTION_H__
 
#include <cstdint>
 
namespace panann {
 
enum class ActivationFunctionType : uint8_t {
  Linear = 1,
  Sigmoid,
  Gaussian,
  Sine,
  Cosine,
  Elliot,
  Threshold,
  SigmoidSymmetric,
  GaussianSymmetric,
  SineSymmetric,
  CosineSymmetric,
  ElliotSymmetric,
  ThresholdSymmetric,
 
  // The symmetric activation functions are grouped at the end so we would
  // know that an activation function is symmetric if it's at least the
  // first one in this group.
  FirstSymmetric = SigmoidSymmetric
};
 
class ActivationFunction {
 public:
  static double ExecuteLinear(double value);
  static double ExecuteDerivativeLinear(double value);
 
  static double ExecuteSigmoid(double value);
  static double ExecuteDerivativeSigmoid(double value);
 
  static double ExecuteSigmoidSymmetric(double value);
  static double ExecuteDerivativeSigmoidSymmetric(double value);
 
  static double ExecuteGaussian(double value);
  static double ExecuteDerivativeGaussian(double value, double field);
 
  static double ExecuteGaussianSymmetric(double value);
  static double ExecuteDerivativeGaussianSymmetric(double value, double field);
 
  static double ExecuteSine(double value);
  static double ExecuteDerivativeSine(double value);
 
  static double ExecuteSineSymmetric(double value);
  static double ExecuteDerivativeSineSymmetric(double value);
 
  static double ExecuteCosine(double value);
  static double ExecuteDerivativeCosine(double value);
 
  static double ExecuteCosineSymmetric(double value);
  static double ExecuteDerivativeCosineSymmetric(double value);
 
  static double ExecuteElliot(double value);
  static double ExecuteDerivativeElliot(double field);
 
  static double ExecuteElliotSymmetric(double value);
  static double ExecuteDerivativeElliotSymmetric(double field);
 
  static double ExecuteThreshold(double value);
 
  static double ExecuteThresholdSymmetric(double value);
};
 
}  // namespace panann
 
#endif  // ACTIVATIONFUNCTION_H__