/*
 fuzzylite (R), a fuzzy logic control library in C++.
 Copyright (C) 2010-2017 FuzzyLite Limited. All rights reserved.
 Author: Juan Rada-Vilela, Ph.D. <jcrada@fuzzylite.com>

 This file is part of fuzzylite.

 fuzzylite is free software: you can redistribute it and/or modify it under
 the terms of the FuzzyLite License included with the software.

 You should have received a copy of the FuzzyLite License along with
 fuzzylite. If not, see <http://www.fuzzylite.com/license/>.

 fuzzylite is a registered trademark of FuzzyLite Limited.
 */

#ifndef FL_GAUSSIAN_H
#define FL_GAUSSIAN_H

#include "fl/term/Term.h"

namespace fl {

    /**
      The Gaussian class is an extended Term that represents the %Gaussian
      curve membership function.

      @image html gaussian.svg

      @author Juan Rada-Vilela, Ph.D.
      @see Term
      @see Variable
      @since 4.0
     */
    class FL_API Gaussian : public Term {
    private:
        scalar _mean;
        scalar _standardDeviation;

    public:
        explicit Gaussian(const std::string& name = "",
                scalar mean = fl::nan,
                scalar standardDeviation = fl::nan,
                scalar height = 1.0);
        virtual ~Gaussian() FL_IOVERRIDE;
        FL_DEFAULT_COPY_AND_MOVE(Gaussian)

        virtual std::string className() const FL_IOVERRIDE;
        /**
          Returns the parameters of the term
          @return `"mean standardDeviation [height]"`
         */
        virtual std::string parameters() const FL_IOVERRIDE;
        /**
          Configures the term with the parameters
          @param parameters as `"mean standardDeviation [height]"`
         */
        virtual void configure(const std::string& parameters) FL_IOVERRIDE;

        virtual Complexity complexity() const FL_IOVERRIDE;
        /**
          Computes the membership function evaluated at @f$x@f$
          @param x
          @return @f$ h \times \exp(-(x-\mu)^2/(2\sigma^2))@f$

          where @f$h@f$ is the height of the Term,
                @f$\mu@f$ is the mean of the Gaussian,
                @f$\sigma@f$ is the standard deviation of the Gaussian
         */
        virtual scalar membership(scalar x) const FL_IOVERRIDE;

        /**
          Sets the mean of the Gaussian curve
          @param mean is the mean of the Gaussian curve
         */
        virtual void setMean(scalar mean);
        /**
          Gets the mean of the Gaussian curve
          @return the mean of the Gaussian curve
         */
        virtual scalar getMean() const;

        /**
          Sets the standard deviation of the Gaussian curve
          @param standardDeviation is the standard deviation of the Gaussian curve
         */
        virtual void setStandardDeviation(scalar standardDeviation);
        /**
          Gets the standard deviation of the Gaussian curve
          @return the standard deviation of the Gaussian curve
         */
        virtual scalar getStandardDeviation() const;

        virtual Gaussian* clone() const FL_IOVERRIDE;

        static Term* constructor();
    };
}
#endif /* FL_GAUSSIAN_H */