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https://issues.apache.org/jira/browse/NUMBERS-143?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17066265#comment-17066265
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Alex Herbert commented on NUMBERS-143:
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A custom hypot implementation has been added to Complex. This uses the method
of Dekker for the high precision sum.
commit: 643e1693b7ba06aa3cc524fb8b83a983a62a6227
> Investigate Math.hypot for computing the absolute of a complex number
> ---------------------------------------------------------------------
>
> Key: NUMBERS-143
> URL: https://issues.apache.org/jira/browse/NUMBERS-143
> Project: Commons Numbers
> Issue Type: Task
> Components: complex
> Reporter: Alex Herbert
> Priority: Minor
> Time Spent: 40m
> Remaining Estimate: 0h
>
> {{Math.hypot}} computes the value {{sqrt(x^2+y^2)}} to within 1 ULP. The
> function uses the [e_hypot.c|https://www.netlib.org/fdlibm/e_hypot.c]
> implementation from the Freely Distributable Math Library (fdlibm).
> Pre-java 9 this function used JNI to call an external implementation. The
> performance was slow. Java 9 ported the function to native java (see
> [JDK-7130085 : Port fdlibm hypot to
> Java|https://bugs.java.com/bugdatabase/view_bug.do?bug_id=7130085]).
> This function is used to define the absolute value of a complex number. It is
> also used in sqrt() and log(). This ticket is to investigate the performance
> and accuracy of \{{Math.hypot}} against alternatives for use in Complex.
>
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