Bar charts, pie charts, line charts, scatterplots / XY, bubble charts…

A classification of chart types

A few weeks ago, I needed a classification of chart types for my book, and reinventing the wheel was the last thing I wanted to do. I started with Andrew's classification and the Juice Analytics version. It's a good starting point, but I couldn't fit it into my work, so I decided to design my own classification (it's always nice to [...]

Why I don’t like bar charts

Pies charts are fun to use, but it's almost impossible for grown-ups to find a good reason for using them at work. So your first, safe-for-work choice is a bar chart. The boring bar chart. I don't like bar charts. There, I said it. This is a little rant about bar charts, but also about the Eurostat. One of my [...]

Strange L-shaped trends

There is not much of a story in the expected evolution of US population, according to the United Nations estimates and projections (1950-2100): (You'll see in a moment why there is a vertical line in 2005.) Things get a little more interesting if you split population by age groups. You can see that population is getting old at the top [...]

Making Excel maps without VBA

If you want to make a choropleth/thematic map in Excel without programming perhaps conditional formatting is all you need. Here is how to do it: Select a few hundred columns and rows; Set width and height to 3 (more or less, depending on the resolutions you want); Set font size to 1; Place a map file over those cells and [...]

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Finally revealed: the optimal number of categories in a pie chart

It's very simple, really: you do not compare proportions in a pie chart. Because a pie chart is not a comparison chart, it's a part-to-whole chart. When you do this: what you really want to do is to compare each slice to the whole, like this: because, if you want to compare them you must do this: I hope that [...]

Chart: Education vs. GDP in Europe

(click to enlarge) I have a single and very simple resolution for 2013: make more charts. Simple charts, just to play with the data. Here is the first one. I like scatter plots with a time dimension, even though data points often look like drunken sperm. When you plot education and wealth in Europe, you always get a chart like [...]

Bars and lines: méfiez-vous des morceaux choisis

So, this data visualization thing is new to you, but you already know enough to avoid basic mistakes (pies, 3D...). While playing with the data, you make these two charts: You already know that a bar chart helps you to compare data points, while a line chart is better at displaying trends, right? But you keep staring at them, not knowing [...]

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Bamboo charts: People at risk of poverty or social exclusion

Here is the percentage of people at risk of poverty or social exclusion in the European Union and a few other countries: We are going to resist the urge to identify them and use our preconceptions against them. Let's dig deeper instead. Some groups are more exposed to the risk of poverty. Let's see what happens when we split the [...]

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The Horizon Graph Is a Reorderable Matrix Too: Unemployment Rate 1976-2012

Here is the draft result of my little weekend project, making horizon graphs in Excel: I'm probably using too many color bands, but I like it! The horizon graph is a very compact way to display lots of data points and a shiny example of how to break the rules for a good cause. It was developed by Hannes Reijner [...]

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Animation, Small Multiples or the Reorderable Matrix? Growth of Walmart, Excel Edition

In data visualization, animation is overrated. OK, it's an interesting option if you can see a clear pattern emerging when displaying data over time/space (and, thanks to animation, we were introduced to this communicator extraordinaire named Hans Rosling). It's fun to make an animated GIF like the one above, but you must see animation as a component of interaction. The [...]