Thematic Maps come to CartoDB
At CartoTowers, we’ve been hard at work preparing some new thematic map visualization options for you to use in CartoDB: Choropleth and Bubble maps. For those of you new to mapping, here’s a quick summary of these two popular cartographic techniques:
Choropleth map
Choropleth maps are one of the most well known thematic maps. Especially suited to mapping densities, these maps are a great way to visualize intensity, and also to explain geographic similarities and differences.
Population density per km2 (www.naturalearthdata.com)
Bubble maps
Bubble, or ‘graduated point symbol’ maps are another approach to mapping data on a numerical range, and work really well when visualising geographic differences in absolute value, such as the total number of people that live in cities.
Populated places in East Coast USA (www.naturalearthdata.com)
Thematic maps come to CartoDB
Today we are launching both these new visualization options for all CartoDB accounts making it easier than ever before to create compelling, data driven geospatial visualizations. Please give them a try and let us know what you think!
To get started, load some data into your CartoDB and select the visualization type dropdown on the map screen. You should see the new mapping options available for you there.
CartoDB Thematic Map Highlights
Automatic partitioning of data
CartoDB makes partitioning your data into colors simple. By analysing and selecting divisions that split your data into equal frequency ranges, CartoDB lays the groundwork for robust thematic mapping.
Beautiful Color Ramps
Inspired by Cynthia Brewer’s color palettes, CartoDB includes 5 preset ramps to help you build understandable, beautiful maps.
Ultimate map customisation
The thematic map toolbox is really the starting point for your data visualization. Once you’ve selected a choropleth style, open up the Carto map style editor to fine tune your visualization: add conditional labels, transparency and more.
Geospatial pre-processing
If your data has absolute figures, you may want to convert your values into densities (such as people per km2 or computers per 1000 people) before you visualize. Using CartoDB’s geospatial processing, you can easily calculate these. Simply create a new column in your data table (eg. my_var_per_km2), and populate it using a SQL statement:
UPDATE my_table SET my_var_per_km2 = (my_var / ST_Area(ST_transform(the_geom, 954009)) /10^6)Look to the Future
We’re really excited to bring these visualizations to all our users, and are already working hard on our next update. With more thematic map options just around the corner, 2012 is shaping up to be a great year for geospatial visualizations!
About CartoDB
CartoDB is a geospatial database on the cloud. More than just hosted PostGIS, CartoDB simplifies geospatial development enabling you to focus on the business details of your app. To learn more, sign up for a free account at www.cartodb.com, and check out our developer site and examples gallery.