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https://issues.apache.org/jira/browse/MATH-1130?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Gilles updated MATH-1130:
-------------------------
Attachment: equalsIncludingNaN.dat
I've attached results of a micro-benchmark of "equalsIncludingNaN".
Your proposed change has better performance up to about 1.64e7 calls.
Beyond that, the current code becomes more efficient.
So, we have opposite arguments depending on usage.
In the "light usage" range, where your code is indeed faster, the absolute time
difference vary from 0.8 to 11 milliseconds (on my machine).
> A new set of functions for copyof, remove and replace a given value on a
> slice of array
> ---------------------------------------------------------------------------------------
>
> Key: MATH-1130
> URL: https://issues.apache.org/jira/browse/MATH-1130
> Project: Commons Math
> Issue Type: New Feature
> Affects Versions: 3.4
> Reporter: Venkatesha Murthy TS
> Attachments: equalsIncludingNaN.dat, math-1130-checknotnan.patch,
> math-1130-precision-equals.patch, math-1130-remove.patch,
> math-1130-replace.patch, math-1130.patch
>
>
> These are utility functions mostly required as part of MathArrays.
> MathArrays:
> =============
> The requirement is as follows:
> a) double[] copyOf(double[] values, int begin, int length) ;
> Similar to most other functions that support slice defined by the array
> part from [begin, begin+length) ;its a requirement to copy a slice which is
> not available (the closest is copyOf(array, int len) which misses out the
> begin index)
> b) double[] removeAll(double[] values, int begin, int length, double
> removable);
> Need a function to remove a value from array slice defined by
> [begin,begin+length) and return the filtered version.
> c) double[] replaceAll(double[] values, int begin, int length, double
> oldValue, double newValue);
> Need a function to replace inplace an oldValue substituted with newValue in
> the array slice defined by [begin,begin+length) and return the original
> complete array with just replaced values only in the segment
> [begin,begin+length)
> MathUtils
> =========
> boolean canEqual(double d1, double d2) ;
> provide a canEqual function that is slightly better than exisitng
> MathUtils.equals. We could also improve existing equals method however.
> So the change here is that the new enhanced canEqual can do a quick check on
> Nans and then move to a detailed Double.compare(..) method. This avoids the
> Double.compare call when any one of them is NaN.
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