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Diffstat (limited to 'fuzzylite/src/term/Sigmoid.cpp')
-rw-r--r-- | fuzzylite/src/term/Sigmoid.cpp | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/fuzzylite/src/term/Sigmoid.cpp b/fuzzylite/src/term/Sigmoid.cpp new file mode 100644 index 0000000..77d7f82 --- /dev/null +++ b/fuzzylite/src/term/Sigmoid.cpp @@ -0,0 +1,98 @@ +/* + 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 <http://www.gnu.org/licenses/>. + + fuzzyliteâ„¢ is a trademark of FuzzyLite Limited. + + */ + +#include "fl/term/Sigmoid.h" + +namespace fl { + + Sigmoid::Sigmoid(const std::string& name, scalar inflection, scalar slope, scalar height) + : Term(name, height), _inflection(inflection), _slope(slope) { + } + + Sigmoid::~Sigmoid() { + } + + std::string Sigmoid::className() const { + return "Sigmoid"; + } + + scalar Sigmoid::membership(scalar x) const { + if (fl::Op::isNaN(x)) return fl::nan; + return _height * 1.0 / (1.0 + std::exp(-_slope * (x - _inflection))); + } + + std::string Sigmoid::parameters() const { + return Op::join(2, " ", _inflection, _slope) + + (not Op::isEq(_height, 1.0) ? " " + Op::str(_height) : ""); + } + + void Sigmoid::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 fl::Exception(ex.str(), FL_AT); + } + setInflection(Op::toScalar(values.at(0))); + setSlope(Op::toScalar(values.at(1))); + if (values.size() > required) + setHeight(Op::toScalar(values.at(required))); + } + + void Sigmoid::setSlope(scalar a) { + this->_slope = a; + } + + scalar Sigmoid::getSlope() const { + return this->_slope; + } + + void Sigmoid::setInflection(scalar c) { + this->_inflection = c; + } + + scalar Sigmoid::getInflection() const { + return this->_inflection; + } + + Sigmoid::Direction Sigmoid::direction() const { + if (not fl::Op::isFinite(_slope) or fl::Op::isEq(_slope, 0.0)) return ZERO; + + if (fl::Op::isGt(_slope, 0.0)) return POSITIVE; + + return NEGATIVE; + } + + Sigmoid* Sigmoid::clone() const { + return new Sigmoid(*this); + } + + Term* Sigmoid::constructor() { + return new Sigmoid; + } + +} |