 |
 |
 |
Gheat |  |
|
|
|
|
|
Gheat | |
|
|
Gheat involves setting up a web application server, and then wiring up your web pages to make calls to that server via Google's JavaScript Maps API.
The server side of Gheat has a few dependencies. The first is Python. You need version 2.5 or newer, because Gheat requires the SQLite library, which was added to the standard library in 2.5. There is also some 2.5 syntax in Gheat. The second is Aspen, which is a Python webserver. Gheat is known to work with Aspen version 0.8. At this point you can download and unpack the Gheat distribution, or check it out or export it from the Subversion repository. The next dependency is an imaging library; Gheat supports both Pygame and PIL (if you install Pygame, you only need the imaging components). You can either install it locally in the __ directory of the Gheat distribution (the virtualenv tool is a great way to manage this directory), or you can install it globally. The pygame backend is three or four times faster than PIL, but PIL is easier to install. The functionality is the same with both.
Once all dependencies are satisfied, run the aspen program within the Gheat distribution, which is an Aspen website root. The Gheat distribution includes a sample database out of the box, so at this point you should be able to hit the webserver now running on your machine and see a heatmap tile. Try this URL: http://localhost:8080/classic/4/4,6.png.
If you see an image like in Figure 2.1, then congratulations! You have successfully installed the Gheat server.
Once you get the server running, you need to set things up on the client side. First, you need to embed a Google Map on a web page. Then you need to define a new map layer using GTileLayer and GTileLayerOverlay. There is an example at example.html in the Gheat distribution to get you started. With your Gheat server running, hit http://localhost:8080/example.html to see it in action (you may need to tweak the Google Maps API key). If it works, you will see the heatmap tiles loaded overtop of the underlying Google Map, and you will feel pumped.
See Also:
|
|
|
Gheat | |
|
|
