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Date: Mon, 13 Feb 2012 15:28:59 +0000 (UTC)
From: "Thomas Neidhart (Commented) (JIRA)" <jira@apache.org>
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Subject: [jira] [Commented] (MATH-745) up to 5x Performance Improvement on
 FasFourierTransformer.java by using a recursive iterative sumation Approach
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    [ https://issues.apache.org/jira/browse/MATH-745?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13206931#comment-13206931 ] 

Thomas Neidhart commented on MATH-745:
--------------------------------------

I have tested with different values of sample points, showing always the same results: loop variant slightly faster. Having a N of &gt; 2 ^13^ then leads to the expected StackOverflowException.
                
> up to 5x Performance Improvement on FasFourierTransformer.java by using a recursive iterative sumation Approach
> ---------------------------------------------------------------------------------------------------------------
>
>                 Key: MATH-745
>                 URL: https://issues.apache.org/jira/browse/MATH-745
>             Project: Commons Math
>          Issue Type: Improvement
>    Affects Versions: 3.0
>            Reporter: Leandro Ariel Pezzente
>              Labels: FFT, Fast, Fourier, Transform
>         Attachments: FastFourierTransformer.patch.txt
>
>
> By swithinch form a loop iterative approach to a recursive iterative approach on fastFourierTransformer.java a Perfomance Improvement of up to 5x is gained.

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