Creating a Presentation with R

In this post I’ll look at creating a presentation using the R ecosystem. I’ve used beamer before, and I love it, but I haven’t used the knitr R package yet. Incidentally, the creator of knitr, Yihui Xie, does not like beamer. This is fine, I have been wrong about technology before–I recall thinking in college that facebook was for losers and that it would never catch on. Anyway, Yihui’s work is really impressive and I strongly suggest checking it out.

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Updating R from the Command Line

This is a tiny post, but if I lumped it as an aside into a longer post I might never find it again. If you’re trying to keep up with Hadley Wickham you might need to update R from time to time. The installr package is there to help you keep up with the Wickhams. To update R, just follow the following steps:

install.packages("installr");
library(installr);
updateR();

For further infromation, check out this r-statistics post on the topic.

Getting Started with MongoDB and Python

In this post I’ll walk through getting started with MongoDB using the Python PyMongo module. I’ll go through the installation process, and then walk through an example of entering data into a MongoDB through Python. (In a future post I’ll cover querying documents.) For the installation, I’ll assume that you’re running Ubuntu, but there are instructions for all major operating systems on the link that I have provided.

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Hypothesis Testing in R

In this post I’ll look at different statistical hypothesis tests in R. Statistical tests can be tricky because they all have different assumptions that must be met before you can use them. Some tests require samples to be normally distributed, others require two samples to have the same variance, while others are not as restrictive.

We’ll begin with testing for normality. Then we’ll look at testing for equality of variance, with and without an assumption of normality. Finally we’ll look at testing for equality of mean, under different assumptions regarding normality and equal variance.

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