1Statistics::DescriptiveU:s:eSrmoCootnShtterarit:bi:usEttxeipdcosnP:ee:nrDtleisaDclor(ci3up)mteinvtea:t:iSomnoother::Exponential(3)
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6 Statistics::Descriptive::Smoother::Exponential - Implement exponential
7 smoothing
8
10 version 3.0701
11
13 use Statistics::Descriptive::Smoother;
14 my $smoother = Statistics::Descriptive::Smoother->instantiate({
15 method => 'exponential',
16 coeff => 0.5,
17 data => [1, 2, 3, 4, 5],
18 samples => [110, 120, 130, 140, 150],
19 });
20 my @smoothed_data = $smoother->get_smoothed_data();
21
23 This module implement the exponential smoothing algorithm to smooth the
24 trend of a series of statistical data.
25
26 This algorithm works well for unsmoothed data build with big number of
27 samples. If this is not the case you might consider using the "Weighted
28 Exponential" one.
29
30 The algorithm implements the following formula:
31
32 S(0) = X(0)
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34 S(t) = C*S(t-1) + (1-C)*X(t)
35
36 where:
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38 · t = index in the series
39
40 · S(t) = smoothed series value at position t
41
42 · C = smoothing coefficient. Value in the [0;1] range. 0 means that
43 the series is not smoothed at all, while 1 the series is universally
44 equal to the initial unsmoothed value.
45
46 · X(t) = unsmoothed series value at position t
47
49 version 3.0701
50
52 $stats->get_smoothed_data();
53 Returns a copy of the smoothed data array.
54
56 Fabio Ponciroli
57
59 Copyright(c) 2012 by Fabio Ponciroli.
60
62 This file is licensed under the MIT/X11 License:
63 http://www.opensource.org/licenses/mit-license.php.
64
65 Permission is hereby granted, free of charge, to any person obtaining a
66 copy of this software and associated documentation files (the
67 "Software"), to deal in the Software without restriction, including
68 without limitation the rights to use, copy, modify, merge, publish,
69 distribute, sublicense, and/or sell copies of the Software, and to
70 permit persons to whom the Software is furnished to do so, subject to
71 the following conditions:
72
73 The above copyright notice and this permission notice shall be included
74 in all copies or substantial portions of the Software.
75
76 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
77 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
78 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
79 IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
80 CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
81 TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
82 SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
83
85 Shlomi Fish <shlomif@cpan.org>
86
88 This software is copyright (c) 1997 by Jason Kastner, Andrea Spinelli,
89 Colin Kuskie, and others.
90
91 This is free software; you can redistribute it and/or modify it under
92 the same terms as the Perl 5 programming language system itself.
93
95 Please report any bugs or feature requests on the bugtracker website
96 <https://github.com/shlomif/perl-Statistics-Descriptive/issues>
97
98 When submitting a bug or request, please include a test-file or a patch
99 to an existing test-file that illustrates the bug or desired feature.
100
102 Perldoc
103 You can find documentation for this module with the perldoc command.
104
105 perldoc Statistics::Descriptive::Smoother::Exponential
106
107 Websites
108 The following websites have more information about this module, and may
109 be of help to you. As always, in addition to those websites please use
110 your favorite search engine to discover more resources.
111
112 · MetaCPAN
113
114 A modern, open-source CPAN search engine, useful to view POD in
115 HTML format.
116
117 <https://metacpan.org/release/Statistics-Descriptive>
118
119 · Search CPAN
120
121 The default CPAN search engine, useful to view POD in HTML format.
122
123 <http://search.cpan.org/dist/Statistics-Descriptive>
124
125 · RT: CPAN's Bug Tracker
126
127 The RT ( Request Tracker ) website is the default bug/issue
128 tracking system for CPAN.
129
130 <https://rt.cpan.org/Public/Dist/Display.html?Name=Statistics-Descriptive>
131
132 · AnnoCPAN
133
134 The AnnoCPAN is a website that allows community annotations of Perl
135 module documentation.
136
137 <http://annocpan.org/dist/Statistics-Descriptive>
138
139 · CPAN Ratings
140
141 The CPAN Ratings is a website that allows community ratings and
142 reviews of Perl modules.
143
144 <http://cpanratings.perl.org/d/Statistics-Descriptive>
145
146 · CPANTS
147
148 The CPANTS is a website that analyzes the Kwalitee ( code metrics )
149 of a distribution.
150
151 <http://cpants.cpanauthors.org/dist/Statistics-Descriptive>
152
153 · CPAN Testers
154
155 The CPAN Testers is a network of smoke testers who run automated
156 tests on uploaded CPAN distributions.
157
158 <http://www.cpantesters.org/distro/S/Statistics-Descriptive>
159
160 · CPAN Testers Matrix
161
162 The CPAN Testers Matrix is a website that provides a visual
163 overview of the test results for a distribution on various
164 Perls/platforms.
165
166 <http://matrix.cpantesters.org/?dist=Statistics-Descriptive>
167
168 · CPAN Testers Dependencies
169
170 The CPAN Testers Dependencies is a website that shows a chart of
171 the test results of all dependencies for a distribution.
172
173 <http://deps.cpantesters.org/?module=Statistics::Descriptive>
174
175 Bugs / Feature Requests
176 Please report any bugs or feature requests by email to
177 "bug-statistics-descriptive at rt.cpan.org", or through the web
178 interface at
179 <https://rt.cpan.org/Public/Bug/Report.html?Queue=Statistics-Descriptive>.
180 You will be automatically notified of any progress on the request by
181 the system.
182
183 Source Code
184 The code is open to the world, and available for you to hack on. Please
185 feel free to browse it and play with it, or whatever. If you want to
186 contribute patches, please send me a diff or prod me to pull from your
187 repository :)
188
189 <https://github.com/shlomif/perl-Statistics-Descriptive>
190
191 git clone git://github.com/shlomif/perl-Statistics-Descriptive.git
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195perl v5.28.0 Stati2s0t1i8c-s0:7:-D1e6scriptive::Smoother::Exponential(3)