Neighborhood-Statistics for Samplepoints Based on Raster-Data

There's no ArcGis-tool for calculating neighborhood-statistics for samplepoints based on raster-data: say you had a raster with presence/absence data of a given feature and for a set of samplepoints you wanted to know the feature's occurrence rate (percentage of cells with presence of that feature) in the samplepoints neighborhood, then you will find this model (saved in toolbox NESTPTS.tbx) useful.

Summarize Data by Several Variables

Here's an example how to conveniently summarize data with the cast function (package reshape). By the way you see how this could be done "in-conveniently" by hand. You also see how a for-loop works and how a matrix is constructed and filled. In addition this serves as an illustrative example how flexible "indexing" in R works, as seen in the below loop! (download data) (this example is adapted from https://stat.ethz.ch/pipermail/r-sig-ecology/2011-May/002174.html)

Import dbf to R, Manipulate Strings with grep & sub Function

Here's a set of historical species presence records of a certain geographical region (data-link). I wanted to manipulate / simplify strings (species names) and get an overview of the data. 

...The tasks were to split genera and epitheta, to exclude species with specific strings included and to get rid of unwanted text (author names). For graphical presentation of the species record history I did a plot with segments indicating the first and last year of a species record: