Choropleth Mapping with Mapeteria
This article is part of a series on choropleth mapping, to see other solutions, please visit the introduction here.
Mapeteria operates on the opposite model as Color-It, which is to store coordinates on the generated file itself. Ducky Sherwood, the author, notes that it works well for a small number of coordinates, but becomes unwieldy when more coordinates are added. Essentially, Mapeteria works by taking a gigantic KML file with all of its potential coordinates, and simply modifying the portion of the KML file that controls the coloring. As a result, the generated KML file has all the coordinates, but only some are defined for coloring. The advantage of this is that Mapeteria does not require data to be manually entered. A properly formatted .CSV file is all that is needed to produce the appropriate coloring.
It must be noted that due to the large size of the KML file, only U.S. States, Canadian Provinces and French Departements are included. A key feature however, is the fact that you can map all three types of regions simultaneously. Users must have an appropriately formatted .CSV file in order for Mapeteria to work properly. A link to a convenient how to is given next to the URL box. Once the .CSV file has been posted to a server, enter the URL. The next section relates to Divisors, as Mapeteria has additional data in its KML file. The values in the dataset can be divided by the total population of the region or divided by the square kilometers as reported by the most recent U.S. Census. Colour (clearly a brit here) Mapping refers to what the maximum and minimum values of the data are. Currently, Ducky admits that, “You can have any color you want, as long as it’s red.” The max and min values help Mapeteria determine what values should be what shade. Descriptive text will add whatever additional information to your map. Resolution selection is recommended to be High resolution. Users can elect to see their data on a Google Maps preview, or downloaded in the form of a KML file for viewing in Google Earth.
- Good with large sets of data
- Can simultaneously map different countries
- Open Source! (But lacks any documentation or even comments)
- Slow, large KML files
- Limited database
- Currently only single color
- Size limitations with Google Maps
This was one of the first solutions I came across while doing research. I was fortunate to have gotten a hold of the author who was very helpful in explaining how Mapeteria worked. Unfortunately, she admits that Mapeteria was something of a jury-rigged solution, something that probably needs a few years and a good programmer to fully develop. She has since moved on to other projects, but has opened the source up to Google Code, but lacking any documentation. Mapeteria is realistically only useful for U.S., Canadian and French projects as it was designed. I attempted to increase the size and scope of Mapeteria’s database by adding elements to the generated KML, but Google Maps can only accept a limited number of coordinates. Mapeteria is more of a proof of concept as opposed to a fully functioning application.