text: /*
   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.
   */
  
  #include "fl/term/Ramp.h"
  
  namespace fl {
  
      Ramp::Ramp(const std::string& name, scalar start, scalar end, scalar height)
      : Term(name, height), _start(start), _end(end) { }
  
      Ramp::~Ramp() { }
  
      std::string Ramp::className() const {
          return "Ramp";
      }
  
      Complexity Ramp::complexity() const {
          return Complexity().comparison(1 + 4).arithmetic(1 + 3);
      }
  
      scalar Ramp::membership(scalar x) const {
          if (Op::isNaN(x)) return fl::nan;
  
          if (Op::isEq(_start, _end))
              return Term::_height * 0.0;
  
          if (Op::isLt(_start, _end)) {
              if (Op::isLE(x, _start))
                  return Term::_height * 0.0;
              if (Op::isGE(x, _end))
                  return Term::_height * 1.0;
              return Term::_height * (x - _start) / (_end - _start);
          } else {
              if (Op::isGE(x, _start))
                  return Term::_height * 0.0;
              if (Op::isLE(x, _end))
                  return Term::_height * 1.0;
              return Term::_height * (_start - x) / (_start - _end);
          }
      }
  
      scalar Ramp::tsukamoto(scalar activationDegree, scalar minimum, scalar maximum) const {
          FL_IUNUSED(minimum);
          FL_IUNUSED(maximum);
          return Op::scale(activationDegree, 0, 1, _start, _end);
      }
  
      bool Ramp::isMonotonic() const {
          return true;
      }
  
      std::string Ramp::parameters() const {
          return Op::join(2, " ", _start, _end) +
                  (not Op::isEq(getHeight(), 1.0) ? " " + Op::str(getHeight()) : "");
      }
  
      void Ramp::configure(const std::string& parameters) {
          if (parameters.empty()) return;
          std::vector<std::string> values = Op::split(parameters, " ");
          std::size_t required = 2;
          if (values.size() < required) {
              std::ostringstream ex;
              ex << "[configuration error] term <" << className() << ">"
                      << " requires <" << required << "> parameters";
              throw Exception(ex.str(), FL_AT);
          }
          setStart(Op::toScalar(values.at(0)));
          setEnd(Op::toScalar(values.at(1)));
          if (values.size() > required)
              setHeight(Op::toScalar(values.at(required)));
      }
  
      void Ramp::setStart(scalar start) {
          this->_start = start;
      }
  
      scalar Ramp::getStart() const {
          return this->_start;
      }
  
      void Ramp::setEnd(scalar end) {
          this->_end = end;
      }
  
      scalar Ramp::getEnd() const {
          return this->_end;
      }
  
      Ramp::Direction Ramp::direction() const {
          scalar range = this->_end - this->_start;
          if (not Op::isFinite(range) or Op::isEq(range, 0.0)) return Zero;
  
          if (Op::isGt(range, 0.0)) return Positive;
  
          return Negative;
      }
  
      Ramp* Ramp::clone() const {
          return new Ramp(*this);
      }
  
      Term* Ramp::constructor() {
          return new Ramp;
      }
  
  }
  