I’m (usually) a fan of the R programming language, though in a few ways it lacks features computer scientists expect. For example, R lacks many data structures provided by high-level languages, such as trees, queues, and stacks. This is somewhat complicated by R’s functional nature–R programmers expect data structures to be “persistent,” such that previous versions of the structure are available even after insertions or deletions. Fortunately, data structures in purely-functional languages (generally not R) is a topic of past and ongoing research, spurred initially by Chris Okasaki’s excellent Purely Functional Data Structures. THis implements purely functional stack and queue data structures as described by Okasaki and others, and gives examples of their use, in R. The package, rstackdeque, is available on CRAN, and described in the R Journal.

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These were made between 2012 and 2015, some at a studio in Marquette, MI, and some at the Notre Dame Glass Club.

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There’s a pretty cool app called Codea, which is a programming IDE similar processing.org, but in Lua, on the iPad.

Lua supports first-class functions, so I played around with designing a parameterized L-System which builds sentences as lists of closures.

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I don’t know what made me think it would be a good idea to lug my heavy camera up to the top of South Sister to see the sunrise, but the photos at least turned out ok. Many thanks to Nathan Brown for organizing the trip.

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Climate change is likely to have profound impacts on ecological systems, but in some important cases we’re still a long way from understanding exactly what those impacts might be. For instance, it has been posited that under warming, species in the northern hemisphere will be enhanced at their northern range edge (where presumably species are fitness-limited, and hence range-limited, by the cooler temperatures). Rather, recent research indicates that individual populations of some species may be locally adapted to their climatic environment, such that even these peripheral populations may decline with warming as they have developed an equilibrium with their environment.

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So, I was on TV once. My wife had contacted the Steve Harvey show suggesting I could use a wardrobe makeover. It was quite a surprise to me–we flew to Chicago for filming just a few days after I learned anything about it!

It was a ton of fun, and the Steve Harvey crew and show was a great experience. (And I got some nice clothes out of it.)

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A timelapse video of me making a marble at the Oregon State University Craft Center. Fun fact: the title logo in the video is the result of a custom processing.org program.

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Distributing large data files to all the nodes on a computing network is an important problem in large-scale scientific computing. We developed a more accurate mathematical model for this problem, and although we’ve shown minimum-time distribution to be NP-Hard (construction above), we’ve also developed a logarithmic approximation solution.

This paper was initially presented at COCOON 2011, and later invited for submission to the Journal of Combinatorial Optimization. Thanks Michael Kowalczyk, NMU alum and current Prof, for the pic of me presenting!

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