Month: April 2008

Floating 3D Sankey diagram

Another runner-up in my private “Fancy Sankey Diagram” contest definitely is this Sankey diagram shown on a webpage of the Longford Environmental Alliance (LEA) from Ireland.

It visualizes the “Energy Balance for 2005 as a flow diagram showing our inputs from the left hand side and our outputs or usages on the right hand side.” It is a 3-D image, and kind of floats above the ground, although it doesn’t have a fancy shadow effect as this one does.

I have shown similar diagrams for California, Japan, Sri Lanka, Scotland and the U.S. before. In these national energy balances the various energy sources are shown as entries from the left, while consuming sectors (or the “sinks”) are displayed as output arrows. This Irish Sankey diagram distinguishes ‘Agriculture’ as a separate sector.

Well done √Čire, home of late Mr. Sankey…

Steel Factory Material Flows Sankey Diagram

This 1996 article on Energy Conservation Management (source: Charles M. Gottschalk: Industrial Energy Conservation, UNESCO Energy Engineering Series, John Wiley & Sons Ltd., Chichester, West Sussex, UK, 1996) has a Sankey diagram of the energy flow in a boiler system (will post that one separately one day, maybe). It also features the following steel factory material flow chart (flows are in MT per month, although the text says it is in tons/month):

I took this and converted it to a Sankey diagram, to better comprehend where the real material flows are, and where the biggest losses occur. Losses are distinguished from the other material flows with a
darker blue color. I actually produced two different versions: the first one sticks very closely to the original layout of the processes, the second one has more of a top-down flow direction.

I was unable to hook the flows to the corner of a process node as it is done in the original diagram (e.g. flow from cold mill to slitter line), Also, the little “bridges” where the arrow from circling to annealer crosses the three other arrows, cannot be reproduced in the same way with the tool I am using.

In the second version I need more space, but I think it is much more comprehensible as it sticks to a top-down flow direction. Losses branch off sideways. I added arrow heads for very thin arrows, otherwise they would sometimes be hardly visible. I refrained from putting the units behind each value to keep it like in the original.

Seems as if I have to much spare time, but this ain’t true…

Software Development Bugs Breakdown

This is an interesting one: Saveen Reddy shows a Sankey diagram-like breakdown of bugs in a software development project. The term ‘bug’ is used “…very generically to describe any issue being tracked, not only defects in source code.”.

This does not fully classify as a Sankey diagram, I think, because the arrows don’t seem to reflect any quantities (number of bugs, time spent on bugs, …). But just like the diagram that showed the number of people having been accused and the turnout of the cases I showed here in June 2007, it visualizes a sequence of breakdowns, leading to decisions that are taken (dashed line arrows).

Now, anybody wants to check their bug tracking tool and show a similar diagram but with real numbers?

A hand-drawn goodie

Browsing for more Sankey diagram goodies the other day I was delighted to find the following sketch in a brochure ‘Let’s learn about energy: a practical handbook for teachers’ published by the TACIS technical dissemination project.

The diagram illustrates a list of suggested activities for students, to teach them “why energy is important”:

Get students to draw up Sankey diagram (Figure 3) showing the energy flows through a process or activity. Consider a power station, house or car. The width of the arrows represents the amount of energy. Energy inputs (fuels, electricity) usually flow into the process from the left and useful energy outputs (heating lighting mechanical power, chemical energy) and losses (heat, noise etc.) flow out to the right.

And another language for my collection of Sankey definitions

Software: Energy Flow Sankey for Private Homes

A software with a Sankey diagram feature that I hadn’t noticed before, and only now have added to the list of Sankey Software tools is CASAnova (new house). From what I understand this freeware tool was the result of a research project at a German university that ran from 2000 to 2002.

The program ‘CASAnova – An Educational Software for Energy and Heating Demand, Solar Heat Gains and Overheating Risk in Buildings’ is designed for an easy-to-use handling in order to get an intuitive understanding of the relations between building geometry, orientation, thermal insulation, glazing, solar heat gains, heat energy demand, heating and primary energy as well as overheating in summer.

CASAnova can be used to enter numerous parameters for a building, such as geometry, window and wall areas and types, insulation, heating system, and climate data etc. The tool will eventually produce a generic Sankey diagram of energy flows as the one above. I have just installed it and played around a little bit only to get an impression. CASAnova is available in German and English. Recommended. now on WP 2.5

I have updated from WordPress 2.3.3 to the long-awaited version 2.5. While the visitors of the blog might not even notice any difference, the management of the blog via the admin dashboard looks much more comfortable and cleaner to me. I have already played with the improved tags (tags are also visible in the footer of each post again), but still have to experiment with the new built-in galleries. Kudos to the guys at WP, you’ve done a good job. And thanks King Louie for helping me with the update!

Just for fun – here’s my Sankey-diagram-like schematic display of the upgrade to WP 2.5. The magnitude of the arrows this time do NOT represent anything (neither lines of code nor the amount of satisfaction with each feature….)