I really liked Will Stahl-Timmins’ article on how he developed an infographic on energy consumption in a city.

Will’s blog is called ‘Seeing is Believing’ and his central claim is that information graphics are “the visual transformation of data into understanding”. I agree: infographics are more than just a diagram and labels. They are much more “visual” and their design elements add to a better understanding. Diagrams convey data, infographics convey information. Typically they also have a broader audience: you would find a diagram in a scientific paper, but an infographic in a daily newspaper.

The article ‘Visualising city energy policies’ gives a very good insight into the reasoning of an infographer/designer when creating an infographic. Will describes how he started out from an ordinary Sankey diagram, to get to an infographic step-by-step. This involved studies of different alternatives, sketches on paper, discussions with colleagues, presentations, and many different versions of the infographic in Illustrator…

He experimented with an isometric or what he calls a “pseudo-3D” perspective, but also discovered some shortcomings in using them.

Crossing arrows were an issue. So were the stacked nodes (cubes) that hid parts of flows and were difficult to label.

The “intermediate” outcome of his meticulous work was the below infographic. It seemed to have been a long learning process to achieve this result.

Will went on to include feedback he had gotten from fellow researchers, and decided to add more information on imported energy. At the same time he had to reduce the level of detail. This is the final infographic.

Good work, I think! The resulting infographic is not a genuine Sankey diagram anymore. There are only three arrow widths left, quantities are clustered in these groups. But as I said, an infographic has a different purpose.

It is not mentioned clearly how this infographic will finally be used, and who the target audience is. I imagine it will be used as an illustration in a brochure that summarizes the findings of the URGENCHE project, but to a wider, non-technical audience.

Make sure you read the full blog post at ‘Seeing is Believing’.

Rob has made a new online tool for distribution diagrams using d3.js. Read more about it here. Sankeybuilder.com can be tried out at the heatmap.ca website.

I added Sankeybuilder.com to the list of Sankey software.

Ecowest’s Marc Tobin has this video on Sankey diagrams up on his Youtube channel. He uses LLNLs energy flow diagrams to explain differences in the energy pattern in the 11 western states.

I particularly like it when he comments that Sankey diagrams are much appreciated by “data visulization nerds”… (check out from 0:28).

Over at the TeX – LaTeX Stack Exchange (a Q&A site for users of TeX and LaTeX) this article explains “How to draw a Sankey Diagram using TikZ”. Okay, its a bit techie, but the results look good.

The original poster wanted to know how to draw a Sankey diagram using the TikZ package (TikZ is a “higher-level drawing language built on top of the PGF graphics framework”).

User Paul Gaborit came up with this example using TikZ and building his own sankeydiagram environment

The interesting thing is that flows can fork and join, and that there is a check that the sum of quantities must be equal to the quantity of sankey node to fork.

This is how the the original sample Sankey diagram looks like with this solution.

Very nice result. So for those out there used to working with TeX/LaTeX out this is actually a good solution.

Don’t miss to read the comments too (there’s one pointing to an alternative (Matplotlib and Sankey module).

I swear I didn’t create this one … found it here. It really made me smile.

Promise I will make more Sankey diagrams!

After my last pic of a twitter conversation on Sankey diagrams I got some thumbs up for the idea. So, here is a another one for your casual friday. Enjoy!

Back at my desk after the holiday season…. Happy New Year to all of you. To start off the blogging this year, here is a funny twitter conversation on Sankey diagrams.

Quite an impressive number of ?s and !s…. and, well, geography is more interesting anyway. ;-)

This legacy article on ‘Solar Energy System and Design’ by W.B. Stine and R.W. Harrigan (published in 1985 already) has four Sankey diagrams for energy flows in a solar power system.

The old-school black&white Sankey diagrams depicted have a general vertical orientation, and some flows branch out to the left of the general flow direction. This is OK, but the first branch flow bends with an angle larger than 90° degrees, performing an almost U-turn.

In the next diagram this idea is doomed to fail as the Sankey arrow to the left is wider than the one going straight on, and the initial parallel segment is much too short.

Additionally in this second Sankey diagram the two arrows at the bottom don’t add up with their flow quantities correctly (633 kW + 244 kW is not 1008 kW).