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Make distance calculation more stable #134

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jenetics opened this issue Oct 16, 2020 · 1 comment
Closed

Make distance calculation more stable #134

jenetics opened this issue Oct 16, 2020 · 1 comment
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enhancement
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v2.1.0

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@jenetics
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The current implementation for calculating the distance between two points contains code, where values are checked against zero.

// Eq. 17 Careful! sin2sigma might be almost 0!
final double sinalpha = sin2sigma == 0.0
	? 0.0
	: cosU1cosU2*sinlambda/sinsigma;

This kind of comparison isn't numerically stable. Replace this code with an epsilon check.
@jenetics jenetics added this to the v2.1.0 milestone Oct 16, 2020
@jenetics jenetics self-assigned this Oct 16, 2020
jenetics added a commit that referenced this issue Oct 16, 2020
@jenetics
#134: Add epsilon 'equals' method.
84705c0
jenetics added a commit that referenced this issue Oct 16, 2020
@jenetics
#134: Improve 'equals' method.
64c98f4
jenetics added a commit that referenced this issue Oct 16, 2020
@jenetics
#134: Stabilize 'distance* method.
ca0cfb3
jenetics added a commit that referenced this issue Oct 16, 2020
@jenetics
Merge pull request #135 from jenetics/issues/JPX-134-stable_distance
5c7fb4d 
#134: Stable distance method
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Merged into r2.1.0 branch.

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