How about… CartoDB?

Mapping is one of the most sought-after techniques in data driven journalism. In contrast to line and bar charts, maps are much easier accessible for people, who are afraid of numbers (even though no one should be!).

There are several tools out there to create your own maps. One of the most popular ones is CartoDB. We are not saying it’s the best one or the only usable one. In contrary, the selection of tools is always highly based on your abilities and goals. However, we gave CartoDB the chance to convince us.

Is it made for me?

CartoDB Hello

The tool makes it easy for beginners to get started right away

Everyone can use CartoDB! You as well. It doesn’t require any programming skills to get started – even though it can be a plus – and the tool is quite comprehensible. An easy to access user-interface leads you from a data-set to a finalized map, step by step.
That doesn’t rule out any hick-ups on your first attempt. Like for almost everything, a learning curve is required. But no worries, you don’t need to climb as high as Edmund Hillary when he reached the summit of Mount Everest.

Let’s get started – the data

First things first: you should have an idea about what information you want to put on the map. Even though CartoDB allows for exploring your data, it’s not its strongest feature. Rather, you should already have a know what’s in your data-set. If anything is missing, you can always add additional information, e.g. by merging two data-sets. During our experiment we tried the function to merge data sheets and it worked out just partially fine. We needed several attempts to get it right. So better get your data in order before you start up CartoDB.

We based our map on data provided by the European Union. On the website ‘Budget On Line’ the total revenue of the general budgets of the European Union of several fiscal years are published. We put the focus on the national amount that every member state contributes to the general budget in 2015. The data in question was accessible through a PDF (total revenue 2015) and could simply be copied and pasted to Excel.

Besides the names of the member states and the appertaining total national contribution to the EU budget (in Euro), we added some informative data. For one, we included two rows containing the annual contributions of the member states in the previous year (2014) and the difference of both years in percentage. Furthermore, we calculated the proportion of contribution by member state. You can find the data-set here.

CartoDB offers you several options to integrate your data. You can either create your own set using Excel, as we did, then drag and drop the file into CartoDB. Or you can connect data stored in either Google Drive, Dropbox or other storage services directly to your account. Alternatively, CartoDB provides you with a bunch of preset data-sets in their ‘Data Library’.

Visualize it!

Once you have uploaded a data-set, we recommend to double check whether CartoDB’s automated mapping of rows worked correctly. For instance the countries’ names need to be identified as polygons and strings and the amounts and percentages need to be displayed as numbers. In our case the automated recognition worked out quite well; in a pre-test we had some troubles with punctuation (commas vs. dots) in numbers that we solved easily in Excel.

CartoDB Screenshot Use Case

Once the data is uploaded you can instantly visualize the map

The next – and most delightful – step is to visualize the data by clicking on ‘map view’. CartoDB makes several suggestions to its users on what data to base the map on. However, it’s totally up to you to decide what data to map and what additional information to display. In our case, the member states’ contributions to the general budget of the European Union in 2015 are the core information. We decided to visualize the data as a heatmap, staining the countries according a color spectrum from beige (lowest amount) to dark blue (highest amount).

Fine tuning

A slider on the right side enables you to tune your map. Of course your options are limited to some point, but CartoDB offers more possibilities than you might expect at first sight. Most importantly, you decide which kind of map you want to create and what kind of information you want to have displayed when you mouse over the countries. Even though CartoDB provides much more options, these are the ones that helped the most to create an easy understandable, content-rich map.

As aforementioned, we created a heatmap (or a “choropleth” as CartoDB calls it), but depending on the data a visualization based on categories or even bubbles instead of polygons can make more sense. From the ‘info window’ menue you can precisely control which information will be published or not by either playing with the controllers provided or by programming your own (not a must). You can easily customize the information flow with a little knowledge in HTML. For instance, nothing too fancy is required in order to adjust the sub-headlines and to make the given information more precise. The best part is, you don’t need to access the data-set first and edit the information there; you can conveniently do it all in the map view. With simple commands a greater structure and additional, generic information can be displayed. For everyone who is familiar with WordPress, the use of HTML in this context will be a piece of cake. On the downside, editing the imported data is restricted. Only simple adjustments can be done, such as transforming numbers to strings or adding rows. Punctuation, in order to make the data more readable, is not possible. You kind of need to deal with the default settings. Therefore, again, we recommend to prepare the data-set thouroughly before importing it into CartoDB.

Visualization Tool - CartoDB HTML

Not required but helpful: don’t be afraid of HTML. One simple command can improve your map a lot

Next to the slider that offers customization options with regards to countries and information, there are three more toolboxes. Under ‘change basemap’ the map’s interface can be adjusted easily, and under ‘options’ you can add features to the general map, such as a search box to let the user find a country or city (not really necessary for our map), display a fixed title and description and so on. Additionally, ‘Elements’ can be added to the map. Since the fixed description and fixed title have a limitation of characters, we made use of textbox-elements in order to provide our readers with introductory information about the map’s topic.

What we think about it

Even though we mentioned the use of HTML, no programming is required in order to create a first good looking and informative map (as our example shows). But some basic knowledge does come in handy. CartoDB provides clear templates that even help beginners to create great visualizations. As long as you subscribe as a standard user, you don’t need to pay for the tool. Unsurprisingly that goes along with some limitations, such as free storage limited to 250 MB and less options with regards to your profile settings. However, for someone who is not very experienced working with geospatial information, CartoDB is a good choice, if you bring along a bit of patience to get it all worked out. For our example case, we spend almost one day getting to know the tool, creating the final map and more overly finding and refining the dataset. Personally, we had a lot of fun playing around with CartoDB. Not everything went well at first attempt, and there a some minor bugs, but in conclusion the tool is comprehensible and easy to use.

What we like… …and dislike
good for beginners profile settings are not editable for non-paying users
quick learning curve 250 MB free usage is not a lot (2-3 maps)
more options possible than you might think at first glance… …but editing the data is very restricted
no programming required (but is very helpful)
easy to share and embed the final map


Last but not least – our project

About the author : Eva Lopez (DW)