Musings, Explorations, and Announcements

At D-RUG this week Rosemary Hartman presented a really useful case study in model selection, based on her work on frog habitat. Here is her code run through ‘knitr’. Original code and data are posted here. (yes, I am just doing this for the flying monkey) Editor’s note: we’re giving away flying monkey dolls from our sponsor, Revolution Analytics, to all our D-RUG presenters. So, let’s say you want to find out where things are and why they are there.

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Mason Earles gave a great presentation this week at Davis R Users’ Group about linking R with the Forest Vegetation Simulator (FVS). FVS is a model developed by the US Forest Service to simulate forest growth over time. It’s written in FORTRAN and has been around since the 1970s. FVS has recently gone open-source (its repository is on google code), and now has an alpha-level API which can be called from R.

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At Davis R Users’ Group today, Ryan Peek gave a presentation on how he takes data from his field instruments and visualizes it in R. Here are his notes. The original *.Rmd file and data can be found here SHORT HOW-TO ON USING XTS AND GGPLOT FOR TIME SERIES DATA XTS is a very helpful package when working with time series data. I work with temperature and flow data frequently, so the ability to work with timeseries, and particularly to shift intervals (from 15 min to hourly or daily) can be very handy.

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A first draft, just out to my committee. Feedback welcome! A modifiable souce version can be found on github here Abstract Forest disease spreads through plant communities structured by species composition, age distribution, and spatial arrangement. I propose to examine the consequences of the interaction of these components of population structure Phytophthora ramorum invasion of California redwood forests. First, I will compare the dynamic behavior of a series of epidemiological models that include different combinations of population structure.

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The amazing UpGoer5 text editor only allows you to use the 1000 most commonly used words in the english language. Here is my research described using only those words: Sometimes many trees get sick and die very quickly. I look at how death moves between different kinds of trees and how groups of different trees change how fast death moves. I try to figure out when many trees will die together, and the type of things we need to know in order to figure this out ahead of time.

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