Simon Willison’s Weblog

Sunday, 4th April 2021

Spatialite Speed Test. Part of an excellent series of posts about SpatiaLite from 2012—here John C. Zastrow reports on running polygon intersection queries against a 1.9GB database file in 40 seconds without an index and 0.186 seconds using the SpatialIndex virtual table mechanism. # 4:28 pm

Animated choropleth of vaccinations by US county

Last week I mentioned that I’ve recently started scraping and storing the CDC’s per-county vaccination numbers in my cdc-vaccination-history GitHub repository. This week I used an Observable notebook and d3’s TopoJSON support to render those numbers on an animated choropleth map.

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2021 » April

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