![]() It works great on both desktop and touch devices, where you can drag the two shapes with your fingers or pinch to zoom. You can read more on Comparea’s about page or study this nifty diagram: This results in a valid comparison of their areas with minimal distortion for each shape. It lets you answer questions like “how big is Greenland, really?” or “how large would Alaska be if it were in the contiguous US?”Ĭomparea projects the two geographic features using equal area projections with the same scale but different centers. Posted in Uncategorized at 11:33 am by danvkĬomparea is a tool that lets you Comparea Areas. There were 117,211 ways with Wikipedia tags and 156,064 relations. ![]() Here's my full code if you're interested. The wikipedia filtering code ran in ~30 minutes. Running the example_counter binary over, I was able to read something like 2GB/minute of data, so 12-13 minutes for the full file. On Mac OS X, this was what my install sequence looked like: I used libosmpbfreader, which depends on libosmpbf, which in turn depends on protoc. This was much easier than you might expect and, since the file is 25GB and growing, probably worth the effort. Instead, I wrote my own filter using C++. I tried to filter down to just the features with Wikipedia tags using GDAL’s ogr2ogr tool (which supports PBF format), but had no luck. This file is in “PBF” format, an OSM-specific format based on Google’s Protocol Buffers. To make a list of such features, I started with the planet.osm file, which you can download as a Torrent. That’s a hard concept to make precise! One idea is to say that any feature with an associated Wikipedia article is interesting. ![]() There are far too many polygons in OSM to include everything, so you have to filter to “interesting” ones. I’m interested in using OpenStreetMap data to add lots more shapes to Comparea. Posted in Uncategorized at 10:50 am by danvk And I’m very excited about the idea of not hosting my own site- has always felt quite slow to load, but I’ve never quite been sure why. Why do this? Blogging with WordPress feels heavy-weight and inflexible compared to using Markdown and my existing git workflows. I pulled out some highlights from the last eight years here. The blog started as something of a personal journal when I moved to California, but turned more tech-focused and sparse as I started to make more friends in my new home. This was a real trip down memory lane for me. Head on over and leave a comment!Īs part of the move, I read through all eight years of blog posts. For RSS subscribers, you can find the new feed here. Visiting will take you to the new site, from which you can find the new danvk blog. Posted in Uncategorized at 8:59 am by danvkĪfter eight years of blogging with WordPress, it’s time to ditch this 11-year old technology in favor of the merely 6-year old GitHub pages.
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