Using R snippets written by other developers can be unendingly maddening. There are a variety of reasons for this, most of which boil down to a simple issue: most code is written such that a system must be configured in … Continue reading →

Using R snippets written by other developers can be unendingly maddening. There are a variety of reasons for this, most of which boil down to a simple issue: most code is written such that a system must be configured in … Continue reading →

I was interested in modeling the relationship between the power and sample size, while holding the significance level constant (p = 0.05) , for the common two-sample t-Test. Luckily R has great support for power analysis and I found the function I was looking for in the package pwr. To calculate the power for the two-sample T-test

At Davis R Users’ Group yesteray, Steve Culman gave us an introduction to the plyr package and how to use it to manipulate data. Here’s his presentation, and the accompanying demonstration script: Steve’s talk is based on this paper by Hadley Wickham in the Journal of Statistical Software. A lot of useful related...