Google Maps Hacks are turning up everywhere; here are some things we just didn't have time to cover fully.
My kids get sick on curvy roads. It is just a fact of life. One measure of the curviness of a road is the detour index. This is the ratio of the shortest road distance and the straight-line distance. Some mathematicians also call this the "fractal dimension of the polyline."
Detour Index = road distance ÷ straight line distance X 100
We can get the road distance by calculating the driving directions and grabbing that distance. Figure 7-30 shows it is 68.1 miles from Cloverdale to Mendocino.
See "How Far Is That? Go Beyond Driving Directions" [Hack #12] for different ways to calculate the straight-line distance. I used our sample tool at http://mappinghacks.com/projects/gmaps/lines.html. Be careful to measure the same distance! I noted the start and stop points of the Google route and tried to match those in calculating the straight-line distance as shown in Figure 7-31.
Figure 7-30. From Cloverdale to Mendocino is 68.1 miles on the road
Figure 7-31. Straight-line distance from Cloverdale to Mendocino is 55.1 miles
The straight-line distance is 55.1 miles, so the detour index is 68.1÷55.1 X 100=123.6.
Through careful analysis of four or five trips, as partially described in Mapping Hacks, I've determined that a detour index over about 120 is a recipe for carsick fun. If you are a motorcyclist looking for curves, you can use the number for your own ends. But remember, as the heartless half of this book's writing team says, "For some people, motion sickness is no laughing matter. For the rest of us, it is."
We really wanted to turn this into a Google Maps demo that you could experiment with yourself, but we just didn't have the time!
7.10.1. Other Cool Google Maps Hacks
One of the painful challenges in writing this book during the heady days of the release of the official API was that we just could not keep up with all of the cool work that was being done, much less contribute to it ourselves. We'd watch our email, and the Google Maps API mailing list, and Del.icio.us, and more cool "must include" hacks appeared than we could possibly ever write about. Here are a few of the coolest.
126.96.36.199. Google sightseeing.
What could be better than standing on a sunlit peak overlooking the Grand Canyon at sunset with your loving family by your side? How about looking over it without the 10-hour car trip in an overheating station wagon with sticky seats, grumpy children, and a fed-up wife?
We have Google, so why bother seeing the world for real? The Google Sightseeing site at http://www.googlesightseeing.com/ shows neat places on Google Maps. Consider it a map geeks blog: Alex, James, and Olly scour (imagery of) the Earth to bring you landscapes to amuse and amaze.
188.8.131.52. ZIP Code maps.
Postal code boundaries are often a bit arbitrary. You can go to http://maps.huge.info/, enter a ZIP Code, and see the area it covers. Figure 7-32 shows 95472 on a map. ("Examine Patterns of Criminal Activity" [Hack #18] shows another example of rendering arbitrary GIS vector data on Google Maps.)
The site is careful to note its own limitations:
ZIP Code data is derived from the Census 'ZCTAs (ZIP Code Tabulation Areas),' which may be different than the USPS defined ZIP Code delivery routes. A USPS ZIP Code is not a geographical area but a route which may not be definable as a polygon.
184.108.40.206. Google Planimeter.
You can use Google Maps to measure areas at http://www.acme.com/planimeter/. Navigate to your selected area and then click on at least three points, and it will calculate the area. Figure 7-33 shows that the Point Reyes National Seashore is roughly 137 square miles.
Figure 7-32. ZIP Code 95472 displayed on a map
220.127.116.11. Play games on Google Maps.
In Tripods, you "battle invading Google Maps Tripod markers that are invading Manhattan." This is a multiplayer game, so you can gang up with other players to fight the menace, as shown in Figure 7-34. You can play Tripods at http://www.thomasscott.net/tripods/.
Find the Landmark, at http://landmark.mapsgame.com/, gives you a landmark and times your attempts to find it. Figure 7-35 shows my "I give up" time at finding the Space Needle in Seattle.
Other games are discussed on the Games On Google Maps wiki page at http://moloko.itc.it/trustmetricswiki/moin.cgi/GamesOnGoogleMaps.
18.104.22.168. Map versus satellite.
Overlay a small section of a map view over the satellite view, or vice versa, at http://www.kokogiak.com/gmaps-transparencies.html. This helps you to see discrepancies between the map and the imagery, as in Figure 7-36.
22.214.171.124. Edible plants in the public domain.
The Garden of the Commons at http://commonsgarden.org/ maps plants growing in public spaces that have food or medicinal value and offers users the chance to contribute their own finds.
Figure 7-33. Measure the area of Point Reyes National Seashore
126.96.36.199. Animate a route.
There is a bookmarklet at http://www.ergul.com/maps/ that will animate your driving directions, even cross-country. Enter your end points and watch as the computer follows your route for you.
188.8.131.52. Track your credit card spending.
Greg McCarroll has done work on mapping his credit card statement at http://www.mccarroll.org.uk/~gem/creditcardtracker/. Being able to see where you spend money might just help you manage your spending habits!
Figure 7-34. Fight the Tripods!
Figure 7-35. Find the LandmarkThe Space Needle
Figure 7-36. Compare the map with the satellite view
7.10.2. Where to from Here?
We can recommend a couple of web sites that track the Google Maps phenomenon in all its glory and bring you up-to-date on the latest developments. The first is Google Maps Mania, at http://googlemapsmania.blogspot.com/, a veritable cornucopia of Google Maps news and reviews. The other, of course, is our very own Mapping Hacks blog, at http://mappinghacks.com/ where we hope to present a more vaired and in-depth view of the rapidly evolving world of digital cartography, including, of course, Google Maps.
So where to now? Google Maps has provided a brush or two, an easel, and a few pots of paint. Get out there and see what you can make!
The tool on the cover of Google Maps Hacks is an antique globe of the earth. Unlike maps, globes allow for undistorted geographical representations of the earth and other spherical celestial bodies. The earliest known globe, the Nurnberg Terrestrial Globe, was made during the years 14901492 by German navigator and mapmaker Martin Behaim.
The cover image is from the "CMCD Everyday Objects" CD. The cover font is Adobe ITC Garamond. The text font is Linotype Birka; the heading font is Adobe Helvetica Neue Condensed; and the code font is LucasFont's TheSans Mono Condensed.