Initial Posting Due: Tue, Nov 28 at (Canvas Link)
Readings
Finding appropriate readings is hard. The first two are required:
- Arrange Networks and Trees (Chapter 9 from Munzner’s Visualization Analysis & Design) (Munzner-09-ArrangeNetworks.pdf 879 kb)
- TreeVis.net has a huge number of visualizations of trees. Look at the pictures and try to get a sense of how many different ways there are to do this.
Tamara Munzner gave a talk that gets across the point that there are many ways to show a graph. It gets the point across that there are lots of design choices and options. Plus, you’ll get a sense of the person behind the book (although, this was almost a decade ago). But, sitting through the hour is a bit much – so it’s OK to just watch a little bit and read through the slides.
- Tamara Munzner. 15 Views of a Node-Link Graph: An InfoVis Portfolio, Google TechTalks, Mountain View CA, 6/06. Talk video (Video on YouTube) (slides)
I wanted to find a survey paper that covered the more computational aspects (the layout algorithms). I haven’t found one that I like. Instead, I am recommending this paper. Read it to get a sense of what the basic methods are – don’t try to get at all the details and subproblems and …
- von Landesberger, T., Kuijper, A., Schreck, T., Kohlhammer, J., van Wijk, J. J., Fekete, J.-D., & Fellner, D. W. (2011). Visual Analysis of Large Graphs: State-of-the-Art and Future Research Challenges. Computer Graphics Forum, 30(6). doi:10.1111/j.1467-8659.2011.01898.x (official version) (authors’s copy)
Optional
There is a lot out there. One good general source for background is the book “Handbook of graph drawing and visualization” – which you can find drafts of the chapters online. In particular, the Chapter on Force-Directed Layout (at least the beginning parts of it) gives a review of the classical algorithms.
- Kobourov, S. (2016). Force-Directed Drawing Algorithms. In Handbook of Graph Drawing (pp. 383–408). (pdf online)
For a modern algorithm for small to medium graphs:
- Dwyer, T. (2009). Scalable, Versatile and Simple Constrained Graph Layout. Computer Graphics Forum, 28(3), 991–998. (pdf) (doi)
It’s a modern take on graph layout. It considers many aspects about what makes for a good layout, and uses real optimization methods to achieve them. The method gives a sense of the evolution and all the methods that came before it). This might be a little too CS-technical for most people. Don’t worry about the details of the algorithms, but get a sense of the kinds of things the best algorithms try to achieve. In practice, people usually use simpler algorithms (force-directed layout)
Online Discussion
Initial Posting Due: Tue, Nov 28 at (Canvas Link)
For this week’s discussion prompts, here are two questions that will hopefully help you connect the readings to problems you encounter (like the Design Challenge).
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When you look at the treevis.net website, you can see a lot of different ways to represent a tree (which is a special kind of graph). Pick one that you found surprising/weird (at least from the picture, you don’t need to read the paper). What do you think is good/bad about it? Why did you think the author made it? Does the design extend to the more general case of a directed graph?
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A node-link diagram is the standard way to show graph data – but it’s clearly note the only one. What are the pros and cons of a node link diagram?
