/*
Author: Juan Rada-Vilela, Ph.D.
Copyright (C) 2010-2014 FuzzyLite Limited
All rights reserved
This file is part of fuzzylite.
fuzzylite is free software: you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free
Software Foundation, either version 3 of the License, or (at your option)
any later version.
fuzzylite is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
for more details.
You should have received a copy of the GNU Lesser General Public License
along with fuzzylite. If not, see .
fuzzyliteâ„¢ is a trademark of FuzzyLite Limited.
*/
#include "fl/term/Cosine.h"
namespace fl {
Cosine::Cosine(const std::string& name, scalar center, scalar width, scalar height)
: Term(name, height), _center(center), _width(width) {
}
Cosine::~Cosine() {
}
std::string Cosine::className() const {
return "Cosine";
}
std::string Cosine::parameters() const {
return Op::join(2, " ", _center, _width) +
(not Op::isEq(_height, 1.0) ? " " + Op::str(_height) : "");
}
void Cosine::configure(const std::string& parameters) {
if (parameters.empty()) return;
std::vector 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 fl::Exception(ex.str(), FL_AT);
}
setCenter(Op::toScalar(values.at(0)));
setWidth(Op::toScalar(values.at(1)));
if (values.size() > required)
setHeight(Op::toScalar(values.at(required)));
}
scalar Cosine::membership(scalar x) const {
if (fl::Op::isNaN(x)) return fl::nan;
if (fl::Op::isLt(x, _center - _width / 2.0)
or fl::Op::isGt(x, _center + _width / 2.0))
return _height * 0.0;
const scalar pi = 4.0 * std::atan(1.0);
return _height * (0.5 * (1.0 + std::cos(2.0 / _width * pi * (x - _center))));
}
void Cosine::setCenter(scalar center) {
this->_center = center;
}
scalar Cosine::getCenter() const {
return this->_center;
}
void Cosine::setWidth(scalar width) {
this->_width = width;
}
scalar Cosine::getWidth() const {
return this->_width;
}
Cosine* Cosine::clone() const {
return new Cosine(*this);
}
Term* Cosine::constructor() {
return new Cosine;
}
}