NeuronLinear.h

/**
 * DESCRIPTION OF THE CLASS
 *
 * @author Martin Beseda
 * @author Martin Mrovec
 * @author Michal Kravčenko
 * @date 2017 - 2018
 */

#ifndef INC_4NEURO_NEURONLINEAR_H
#define INC_4NEURO_NEURONLINEAR_H

#include "Neuron.h"

namespace lib4neuro {

    /**
     * Linear neuron class - uses activation function in the form f(x)=a*x + b,
     * 'x' being the neuron's potential
     */
    class NeuronLinear:public NeuronDifferentiable {

    public:

        /**
         * Struct used to access private properties from
         * the serialization function
         */
        struct access;

        /**
         * Constructs the object of the Linear neuron with activation function
         * f(x) = x + b
         * @param[in] b Bias
         */
        LIB4NEURO_API explicit NeuronLinear( );

        /**
         * Evaluates 'x + b' and stores the result into the 'state' property
         */
        LIB4NEURO_API double activate( double x, double b ) override;

        /**
         * Calculates the partial derivative of the activation function
         * f(x) = x + b at point x
         * @return Partial derivative of the activation function according to the
         * 'bias' parameter. Returns 1.0
         */
        LIB4NEURO_API double activation_function_eval_derivative_bias( double x, double b ) override;

        /**
         * Calculates d/dx of (x + b) at point x
         * @return 1.0
         */
        LIB4NEURO_API double activation_function_eval_derivative( double x, double b ) override;

        /**
         * Returns a pointer to a Neuron with derivative as its activation function
         * @return
         */
        LIB4NEURO_API Neuron* get_derivative( ) override;

    };

}

#endif //INC_4NEURO_NEURONLINEAR_H