Sample Apps Using VT Open Geodata Portal
An app hosted on Mapbox created with Mapbox-GL
<view>the code</view>
I wanted a map showing the age of Burlington buildings (inspired by Age of LA).
Data Sources: A shapefile containing Vermont building outlines was found here, and property information containing the year built was found on the Burlington City Data Portal.
Data Processing: I had to find a way to join each line of property information (which had the year built) with a building outline. This is accomplished with qGIS (free ArcGIS).
The only location information associated with the property information is the center point of the property in Latitude and Longitude (-73, 44). In order to import and use this location information in qGIS (and many other GIS programs), I had to use Excel to break out the Latitude and Longitude into their own fields using the formulas found here.
I imported the buildings shape file and the property data into qGIS. Then I generated the center point for each building using Polygon Centroid under Vector --> Analysis Tools. I could then create a Distance Matrix showing the closest building center point to each property center point. This was a pretty accurate way to join each building outline with its property information. Then I used joins to join the property data with the distance matrix and the buildings shapefile, created a layer out of this information and downloaded it as a shapefile.
Map Style: In mapbox I created a style and uploaded this shapefile as a tileset. Then I added the tileset as a layer, and to the right of the layer -> Style -> Color select there is a steps icon which allows you to color buildings differently according to a property.