derrickpelletier/geohash-poly

Transform a geoJSON MultiPolygon or Polygon into a list of geohashes that form it.

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geohash-poly's Issues

npm audit show vulnerable package

I installed the package and now npm show me this warning about a vulnerable package included in the dependencies.

Probably it just to upgrade a package. I think I can make a PR for this.

Performance increase idea

when the current row intersection is performed, and the poly is returned which represents the parts of the original poly that fall within the current row, rather than starting at the leftmost edge of the current row in the entire bounding box, we really only need to start at the leftmost edge of the bounding box of that poly that was returned.
and similarly end at the eastern extent.

This would save a lot of wasted checks. A turf.extent() would need to be performed for every row.

Write tests

Really need some tests for this.

Return different geohash level

Dear sir, could I return different geohash level (precision) in one run? Beside it, could you tell me more details about your algorithm? How can you find the row bounding? Does it look like the image below? Another problem that I still don't understand is that how you build the row hash (the size, the offset)?
Thanks in advance!

Options for what constitutes coverage

Currently the geohash centre point must be within a poly to pass as being part of the poly. This allows dealing with a large amount of shapes that are flush, there would be no overlapping hashes. In many cases there will be parts of the poly that are not covered by a geohash.

Would be nice to specify an option where coverage infers that the poly is entirely covered. Would require intersection detection I think.

Massive polygon throws an error from turf

Error: Each LinearRing of a Polygon must have 4 or more Positions.

When attempting to run the streaming example on the massive polygon.

Make cli accept a filepath

right now it's just accepting the string of a poly coordinates. Would like it to accept a geojson file perhaps.

hashMode 'intersection' bug (?) and workaround

Hi,
first of all thank you for your work and this great tool. It's really quite fast compared to other approaches.

I found a bug that occurs when using the hashMode 'intersection':
When you specify 'intersection' only (without a threshold) it includes geohashes which do not even touch the polygon:

geohashpoly({coords: coords, precision: 8, hashMode: "intersect" ....

results in:

A workaround is using a really small threshold:

geohashpoly({coords: coords, precision: 8, hashMode: "intersect", threshold: 0.0001} .....

results in:

The second case should be the default behavior in my opinion.

Since it's easy to use a small threshold, a fix might not be needed but one should know about this issue, that's why I'm posting it here.

Best regards!