Map Scripting

Perhaps you’ve seen those maps with geographic regions shaded particular colors? That’s called a Choropleth map and you can create one for U.S. states using simple polygons in Mapstraction.

In order to create these shapes, you need the latitude/longitude points that make them up. For some states, that means many points. It takes a lot of work to collect the data, but Rakshith of MapMash has saved us all work.

You can download the state boundaries XML, or see one of the two JavaScript-ready versions below.

First, this follows the simple Four Corners Example from the book, with a variable for each state.

var alaska = [new mxn.LatLonPoint(70.0187, -141.0205),
new mxn.LatLonPoint(70.1292, -141.7291),
... new mxn.LatLonPoint(70.0187, -141.0205)];
var alabama = [new mxn.LatLonPoint(35.0041, -88.1955),
new mxn.LatLonPoint(34.9918, -85.6068), ...
» Simple JavaScript version

A more advanced version uses an object to hold the state name as a key and the collection of points as the value.

var statesobj = {"Alaska": [new mxn.LatLonPoint(70.0187, -141.0205),
new mxn.LatLonPoint(70.1292, -141.7291),
... new mxn.LatLonPoint(70.0187, -141.0205)],
"Alabama": [new mxn.LatLonPoint(35.0041, -88.1955),
new mxn.LatLonPoint(34.9918, -85.6068), ...
» JavaScript object version