In my earlier blog post on the use of maps and mapping within infographics I focused mainly on the use of GIS applications that can create maps as one of their outputs. Here I mentioned among others ESRI ArcGIS and QGIS as examples of proprietary and open source software. The main use of these GIS software packages is – and I realize this may sound odd – not mapping. Although I do not want to get into the almost endless discussion of what GIS is, the presentation possibilities of GIS are only a part of the software. Besides the GIS applications there is a group of mapping software where the main purpose of the software is the visualization of geo data and its geographical features. Also at this point I want to stress that the world is not as black-and-white as I present it here. TileMill and Tableau are examples of tools from this second group.
The free tools list
For some time now Sharon Machlis has maintained a very useful table of free tools for data visualization and analysis at the ComputerWorld website. One of the categories in this list is GIS and Mapping. In this list there is no ESRI because it’s not free, but QGIS is mentioned as being open source GIS software. I have, from the start on, found this list a great resource even though it is not complete and always up-to-date. Two free tools that definitely should be mentioned are TileMill and Tableau Public.
TileMill from Mapbox is as they say themselves “a desktop application for creating beautiful web maps”, it has therefore very limited to no functionality to manipulate the data. It just takes the data from one of the many geo data formats and presents this data as a map. One of the main strengths of TileMill is its style language called CartoCSS that indeed looks very much like the CSS we know from web design. And for the Geo readers, compare it to the OpenLayers stylemap. TileMill is also powerful because they have separated content, data, and style. (I would nearly, like with XML write Semantic, Structure, and Style here).
Another tool that gets mentioned more and more often recently is Tableau Software. The free available Tableau Public has a simple feature to display data that has a geo location added. Like with TileMill it is presentation software, and actually comes close to the dashboard I mentioned in my earlier blog post. The lack of a style language makes it look a little less flexible, and if it comes to the data (for example the postal codes) it is much focused on the big countries. Also the available database connections in the free version are limited. But to use it for basic maps that present the highlights from a dataset without needing the fine grain? It is excellent.
My favorite setup
What I like with both tools mentioned is that they can read the geo data that has been prepared with GIS software like ESRI ArcGIS en QGIS. By shapefiles (both), by direct read from the PostGIS database (QGIS-TileMill), or by linking to the local WMS-server (Tableau). That immediately describes my favorite setup for the mapping part of my infographics. Doing the questioning and preparation of my dataset in the GIS software, creating the right and balanced tables. Then present it with TileMill or Tableau.
The only hurdle is that Sharon Machlis indicates all GIS software in her table mentioned above with a skill level 4: “specialized knowledge in a field”.