##### Class Meetings

- Mon, Nov 26 – Lecture/ICE:Graphs
- Wed, Nov 28 – Lecture:Graph Layout
- Fri, Nov 30 – NO CLASS

##### Week Deadlines

- Reading: Week 13 – Graphs (due Mon, Nov 26 – preferably before class)
- Quiz 13: 13: Graphs (due Tue, Nov 27)
- Online Discussion 13: Graphs (first post due Wed, Nov 28)
- Seek and Find 13: A Graph (due Fri, Nov 30)
- Design Challenge: DC3:Designs (due Fri, Nov 30)

Hope everyone had a good Thanksgiving.

Last week, we spent a lecture on 3D, and then took a lecture to revisit issues of scaling as a way to think more about Design Challenge 3 (which is going on as we speak).

This week, we’ll talk about graphs – which is a big topic. And one you’ve already seen at least some of for DC2. In fact, The TreeVis.NET web site (which is a required “reading” for this week) was recommended on the DC2 assignment.

On Monday, we’ll talk about graphs in general, and we’ll do a little design puzzle to get us thinking about node link layout. Then on Wednesday we’ll talk more about node-link layout.

You may want to look at this week’s learning goals Learning Goals 13: Week 13 – Graphs.

## Readings (due Mon, Nov 26 – preferably before class)

Finding appropriate readings is suprisingly hard.

- Arrange Networks and Trees (Chapter 9 from Munzner’s
*Visualization Analysis & Design*) (Munzner-09-ArrangeNetworks.pdf 0.9mb) - 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: