photo: sfo bart
MySQL offers ENVELOPE() to find the minimum bounding rectangle of a geometric object.
The result is a polygon with four segments, defined by five points. It took me a while to make sense of it, partially because the only documentation that I’ve run across so far for POLYGON() syntax is in the ENVELOPE() function mentioned above. [...]
It’s MySQL spatial data week here, though I am spreading out the posts to, um, ease the pain (or boredom). Anyway, here are some commands/functions I don’t want to forget about later:
Start with an existing table called geometry, add a spatial column and index it:
ALTER TABLE GEOMETRY ADD coord POINT NOT NULL;
CREATE SPATIAL INDEX coord [...]
MySQL has some powerful, and perhaps underused spatial extensions, but the most interesting functions are still unimplemented: “Note: Currently, MySQL does not implement these functions…”
Among those as-yet unimplemented functions is DISTANCE(). Alternatives can be found here and here, though neither is clean or simple. I wonder if a simple MBRContains() is good enough, though…
Plazes, a kinda-cool, formerly networked-based geolocation tool has just been revamped. They’ve been promoting this change for over a month (I got a cool invite to the launch party, but couldn’t make the flight to Germany), and they’re continuing the push now that it’s live. I’ve used the new service for a few days, the [...]
In yet more geolocation news, beermapping.com’s maps to breweries will make my travel planning easier, and my travels boozier.
Hey, it’s casual Friday, take off early and go find a new brewpub for lunch.
beermapping.com, brew maps, breweries, brewery, brewpub, casual friday, geolocation, mapping, maps
Wearing the badge “still beta,” Plazes, the free, network-based geolocation service, now sports a new coat of paint. Among the improvements is the Flash-based badge (above) and a much improved frontpage/dashboard that combines the map of known locations with the map of active users, formerly two separate screens.
On the downside, I sort of miss the [...]
Engadget alerted me to this GPS data logger from Spark Fun Electronics.
The device records up to 440 hours of data to a 256MB SD card in either a simple text file or KML-compatible format that you can display in Google Earth.
I like it, I want one (actually, I want three, and I’ll eventually post [...]
This post started with Ryan sending me this link demonstrating a KML overlay of county borders of his bifurcated state in Google Maps.
Then I found this Roundup of Google’s Geo Developer Day (btw, I so wanted to be at Where 2.0) with tales of the new geocoding feature of the Google Maps API, more details [...]
Here’s an interesting GeoPlace.com article on open source GIS tools, including GIS extensions to PosgreSQL and MySQL. Via The Map Room.
tags: geo world, geocode, geocoding, geographic information system, geography, geolocation, gis, gis development, gis guide, gis tools, map room, mapping, mysql, open source, open source gis, open source tools
I’m a big fan of the WP Geo plugin, but I want more.
My biggest complaint is that I want to insert coordinates using Google Maps or MultiMap URLs, rather than insert them in the modified story editor. So I wrote a bit of code that reads through the URLs in a post, finds the “maps.google” [...]
