ajfriend

6 ms·

1.
by ajfriend 7mo ago
Yes! A Gosper Island in H3 is just the outline of all the descendants of a cell at a some resolution. The H3 cells at that resolution tile the sphere, and the Gosper Islands are just non-overlapping subsets of those cells, which means they
2.
by ajfriend 7mo ago
I appreciate the reply! So, I might be wrong here, but I think we may be talking about two different layers. I’m also not very familiar with the literature, so I’d be interested if you could point me to relevant work or explain where my und
3.
by ajfriend 7mo ago
Very cool! And the prefix queries you mention are what I was trying to get at in another comment, but you explained it better :)
4.
by ajfriend 7mo ago
I agree that the lack of congruency in H3 hexagons can cause weird overlaps and gaps if you plot mixed resolutions naively, but there are some workarounds that work pretty well in practice. For example, if you have mixed resolutions from co
5.
by ajfriend 11mo ago
h3o-zip is really impressive! I've been wanting to play around with it more, and I've been meaning to ask you if you have any good references for that encoding approach. I understand how it works in h3o-zip, but I'd be intere
6.
by ajfriend 2y ago
I have project that's still very much at the experimental stage, where I try to get something similar to this pipe syntax by allowing users to chain "SQL snippets" together. That is, you can use standalone statements like `wh
7.
by ajfriend 2y ago
I don't. And maybe I should have emphasized "and have a data source" more, since its doing a lot of the heavy-lifting in my statement :)
8.
by ajfriend 2y ago
You can use those if they work for your application. One downside would be that you're storing 4 numbers compared to a single `int64` index with H3. You also have to decide how you'll do that binning. Can bins overlap? What do you
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by ajfriend 2y ago
They also only have one type of neighbor. Square grids have 2 neighbor types. Triangular grids have 3.
10.
by ajfriend 2y ago
If you care about that and have a data source, you can add, for example, population density per H3 cell as part of your analysis. That has the additional benefit of denoting the this quantity of interest explicitly , rather than some impli
11.
by ajfriend 2y ago
It depends on if you want to model a point or an area. lat/lng gives you a point , but you often want an area to, for example, count how many people are in that area. A spatial index like H3 provides a grid of area units.
12.
by ajfriend 2y ago
...and use H3 instead! https://h3geo.org/
13.
by ajfriend 2y ago
That map does seem to be using H3 hexagons: https://h3geo.org/
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by ajfriend 2y ago
Oh man, what an exciting opportunity. clears throat The hacker news title seems to mistranslate the original Em dash to an En dash.
15.
by ajfriend 2y ago
We use a submodule in https://github.com/uber/h3-py to wrap the core H3 library, which is written in C. Submodules seemed like a reasonable way to handle the dependency, and, at least for this use case, the approach ha
16.
by ajfriend 2y ago
You can compose SQL with https://ibis-project.org/tutorials/ibis-for-sql-users , which is using https://github.com/tobymao/sqlglot to parse the SQL under the hood. As an alternative to parsing the
17.
by ajfriend 2y ago
One approach I've been enjoying recently in my personal use is to write a light wrapper around DuckDB to enable composable SQL snippets. Essentially like what I have here https://gist.github.com/ajfriend/eea0795546
18.
by ajfriend 2y ago
This DuckDB blog post on range joins might be relevant: https://duckdb.org/2022/05/27/iejoin.html
19.
by ajfriend 2y ago
If you're asking someone for help, it would be nice if you asked in a way that's most convenient for them.
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by ajfriend 2y ago
Excellent textbook examples in there :)
21.
by ajfriend 2y ago
I think that says more about programming today than it does Knuth.
22.
H3 Version 4.0.0(medium.com)
4 points by ajfriend 4y ago|0 comments
23.
by ajfriend 4y ago
What are some good alternatives to SQL?
24.
by ajfriend 5y ago
I typically only rely on the logical parent/child relationship between cells, and containment there is strict even if geometric containment is only approximate. The logical relationship is useful, for example, in providing a compact
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by ajfriend 6y ago
Can you recommend any good books or other resources?
26.
by ajfriend 7y ago
We're definitely still working on H3. We just got a nice, new domain: h3geo.org We're also basically done with a new Python wrapper written in Cython. https://github.com/uber/h3-py/tree/cython We co