Turfjs / Turfjs/turf

Concave not working as expected

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@turf/concave bug
Dominant language
TypeScript
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Description

I'm using this test code w/ node to run "convex" and "concave":
https://gist.github.com/pwinston/89f9aa06abe8441706dc04acf7ba371b

I'm using these points as input:
https://gist.github.com/pwinston/d14826a2d8e02f652b377c68f5e536ab

When I run turf.convex the output is as expected:
https://gist.github.com/pwinston/441f7d69de25ab9fea47cc286a9c68f8

When I run turf.concave it looks the same as the convex output:
https://gist.github.com/pwinston/b6308219c3741f5f17b4c262229f43a9

I tried different values of maxEdge, which I don't quite understand, and it was no better:
1 mile: https://gist.github.com/pwinston/eae46b39901200476f902e3caa8e7a2c
0.1 mile: https://gist.github.com/pwinston/aeaf352fef0959f4d8c94c308ef79584
0.01 mile: https://gist.github.com/pwinston/e09dbe8a3a0034b22df2cf655f5e2f55

I think I'm using turf 5.1.6:
concave_hull@1.0.0 /Users/pwinston/concave_hull
└── @turf/turf@5.1.6 extraneous

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the linked Node reproduction and the @turf/turf 5.1.6 concave entry point, using the provided input points and maxEdge values. Compare the result with the linked convex and concave outputs; done means concave produces the expected non-convex result for this case.

Written by the indexing model from the issue text.

Assessment

Tech stack
javascript, node.js, typescript
Domain
data
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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