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From "Sebb (Commented) (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (MATH-688) "FastMath" contains fractions of constants
Date Mon, 10 Oct 2011 00:13:29 GMT

    [ https://issues.apache.org/jira/browse/MATH-688?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13123811#comment-13123811
] 

Sebb commented on MATH-688:
---------------------------

AFAIK, the calculations will be done at compile time.
                
> "FastMath" contains fractions of constants
> ------------------------------------------
>
>                 Key: MATH-688
>                 URL: https://issues.apache.org/jira/browse/MATH-688
>             Project: Commons Math
>          Issue Type: Improvement
>            Reporter: Gilles
>            Assignee: Gilles
>            Priority: Trivial
>             Fix For: 3.0
>
>
> Fractions such as 1.0 / 3.0, 1.0 / 5.0, ... could be replaced with static final constants.
> In "asinh", for example, the change can sometimes result in more than halving the computation
time (when the argument is in the range of values where the constants are used).
> In absolute times, the gain is not huge, amounting (on my machine) to something like
370 ms for 10 million computations.
> And, of course, the downside will be that these constants will be computed at the loading
of "FastMath", leading to an additional penalty of about 16 divisions at initialization...
:)

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