Mapping Hacks

Plot Statistics Against Shapes #44

Chapter 4, Mapping (on) the Web

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HACK

Hacking the Hack

What if you’re primarily interested in quakes in your immediate neighbor-

hood? In that case, you can specify a bounding box for your map in terms of

latitude and longitude in your config.xml file. Here’s an example that covers

the San Francisco Bay Area:

<north>38.20</north>

<south>37.30</south>

<west>-121.87</west>

<east>-123.00</east>

If a bounding box is specified, worldKit will only display items in the feed

within the bounding box. You only need to provide an image that corre-

sponds to your location. If you don’t have a map of your area handy, we can

offer a couple of suggestions on how to obtain one easily.

First, you might try MapProxy (http://brainoff.com/worldkit/mapproxy/), a

simple web interface to TerraServer, which can fetch U.S. topo maps or

aerial photos, given a ZIP Code and distance. MapProxy generates the corre-

sponding worldKit bounding box configuration for you, as well.

Failing that, you can take one of the world maps, and extract the area corre-

sponding to your bounding box with Photoshop or ImageMagick. To con-

vert the bounding box in latitude and longitude to x- and y-coordinates in

the image, use the following formulas from Table 4-1.

—Mikel Maron

HACK

#44

Plot Statistics Against Shapes Hack #44

Easily render demographic maps in SVG from shapes and CSV or Excel files.

In late 2003,