1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
|
/*
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/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";
}
Complexity Sigmoid::complexity() const {
return Complexity().comparison(1).arithmetic(1 + 4).function(1);
}
scalar Sigmoid::membership(scalar x) const {
if (Op::isNaN(x)) return fl::nan;
return Term::_height * 1.0 / (1.0 + std::exp(-_slope * (x - _inflection)));
}
scalar Sigmoid::tsukamoto(scalar activationDegree,
scalar minimum, scalar maximum) const {
scalar w = activationDegree;
scalar z = fl::nan;
if (Op::isEq(w, 1.0)) {
if (Op::isGE(_slope, 0.0)) {
z = maximum;
} else {
z = minimum;
}
} else if (Op::isEq(w, 0.0)) {
if (Op::isGE(_slope, 0.0)) {
z = minimum;
} else {
z = maximum;
}
} else {
scalar a = _slope;
scalar b = _inflection;
z = b + (std::log(1.0 / w - 1.0) / -a);
}
return z;
}
bool Sigmoid::isMonotonic() const {
return true;
}
std::string Sigmoid::parameters() const {
return Op::join(2, " ", _inflection, _slope) +
(not Op::isEq(getHeight(), 1.0) ? " " + Op::str(getHeight()) : "");
}
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 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 Op::isFinite(_slope) or Op::isEq(_slope, 0.0)) return Zero;
if (Op::isGt(_slope, 0.0)) return Positive;
return Negative;
}
Sigmoid* Sigmoid::clone() const {
return new Sigmoid(*this);
}
Term* Sigmoid::constructor() {
return new Sigmoid;
}
}
|
