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statistics::descriptive::smoother(3pm) [debian man page]

Statistics::Descriptive::Smoother(3pm)			User Contributed Perl Documentation		    Statistics::Descriptive::Smoother(3pm)

NAME

       Statistics::Descriptive::Smoother - Base module for smoothing statistical data

SYNOPSIS

	 use Statistics::Descriptive::Smoother;
	 my $smoother = Statistics::Descriptive::Smoother->instantiate({
		  method   => 'exponential',
		  coeff    => 0.5,
		  data	   => [1, 2, 3, 4, 5],
		  samples  => [110, 120, 130, 140, 150],
	   });
	 my @smoothed_data = $smoother->get_smoothed_data();

DESCRIPTION

       This module provide methods to smooth the trend of a series of statistical data.

       The methods provided are the "Exponential" and the "Weighted Exponential" (see respectively
       "Statistics::Descriptive::Smoother::Exponential" and "Statistics::Descriptive::Smoother::Weightedexponential" for more details).

       This class is just a factory that will instantiate the object to perform the chosen smoothing algorithm.

METHODS

       Statistics::Descriptive::Smoother->instantiate({});
	    Create a new Smoother object.

	    This method require several parameters:

	    method
		 Method used for the smoothing. Allowed values are: "exponential" and "weightedexponential"

	    coeff
		 Smoothing coefficient. It needs to be in the [0;1] range, otherwise undef will be reutrned.  0 means that the series is not
		 smoothed at all, while 1 the series is universally equal to the initial unsmoothed value.

	    data Array ref with the data of the series. At least 2 values are needed to smooth the series, undef is returned otherwise.

	    samples
		 Array ref with the samples each data value has been built with. This is an optional parameter since it is not used by all the
		 smoothing algorithm.

       $smoother->get_smoothing_coeff();
	    Returns the smoothing coefficient.

       $smoother->set_smoothing_coeff(0.5);
	    Set the smoothing coefficient value. It needs to be in the [0;1] range, otherwise undef will be reutrned.

AUTHOR

       Fabio Ponciroli

COPYRIGHT

       Copyright(c) 2012 by Fabio Ponciroli.

LICENSE

       This file is licensed under the MIT/X11 License: http://www.opensource.org/licenses/mit-license.php.

       Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the
       "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish,
       distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to
       the following conditions:

       The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

       THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
       MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
       CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
       SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

perl v5.14.2							    2012-05-15				    Statistics::Descriptive::Smoother(3pm)

Check Out this Related Man Page

Statistics::Descriptive::Smoother::Weightedexponential(3User Contributed Perl DocumentaStatistics::Descriptive::Smoother::Weightedexponential(3pm)

NAME

       Statistics::Descriptive::Smoother::Weigthedexponential - Implement weigthed exponential smoothing

SYNOPSIS

	 use Statistics::Descriptive::Smoother;
	 my $smoother = Statistics::Descriptive::Smoother->instantiate({
		  method   => 'weigthedexponential',
		  coeff    => 0.5,
		  data	   => [1, 2, 3, 4, 5],
		  samples  => [110, 120, 130, 140, 150],
	   });
	 my @smoothed_data = $smoother->get_smoothed_data();

DESCRIPTION

       This module implement the weigthed exponential smoothing algorithm to smooth the trend of a series of statistical data.

       This algorithm can help to control large swings in the unsmoothed data that arise from small samples for those data points.

       The algorithm implements the following formula:

       W(0) = N(0)

       W(t) = ( W(t-1) * CoeffA + N(t) * CoeffB ) / (CoeffA + CoeffB)

       CoeffA = C * ( W(t-1) / (W(t-1) + N(t) ) )

       CoeffB = (1 - C) * ( N(t) * (W(t-1) + N(t)) )

       S(t) = (S(t-1)*CoeffA + X(t)*CoeffB) / (CoeffA + CoeffB)

       where:

       o  t = index in the series

       o  S(t) = smoothed series value at position t

       o  C = smoothing coefficient. Value in the [0;1] range. 0 means that the series is not smoothed at all, while 1 the series is universally
	  equal to the initial unsmoothed value.

       o  X(t) = unsmoothed series value at position t

METHODS

       $stats->get_smoothed_data();
	    Returns a copy of the smoothed data array.

AUTHOR

       Fabio Ponciroli

COPYRIGHT

       Copyright(c) 2012 by Fabio Ponciroli.

LICENSE

       This file is licensed under the MIT/X11 License: http://www.opensource.org/licenses/mit-license.php.

       Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the
       "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish,
       distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to
       the following conditions:

       The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

       THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
       MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
       CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
       SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

perl v5.14.2							    2012-05-15	       Statistics::Descriptive::Smoother::Weightedexponential(3pm)
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