In this third part of the data types series, I'll go an important class that I skipped over so far: factors.Factors are categorical variables that are super useful in summary statistics, plots, and regressions. They basically act like dummy variables t...
Yesterday’s post showed a number of quick coding options for changing text in a basic ggplot. Here’s another two tricks for fine-tuning faceted plots. Again, let’s load our made up data about tooth growth (a real dataset in R, ToothGr...
In case you missed them, here are some articles from October of particular interest to R users. Sponsorships for local R user groups from Revolution Analytics are now open to applicants worldwide. During the landfall of Hurricane Sandy in the US, several R-based apps used public weather and social media data to document its impact, like this timeline of...
In response to last week's post on the rapidly increasing ideology of the US Republican Party, Mike Lawrence suggested another way of looking at the DW-NOMINATE ideology data. Rather than simply looking at boxplots of the congress scores by party over time, we could fit a smooth curve to get a better sense of the trends over time. Mike...
A few days ago a post doctoral researcher asked me if I could help him reorder the factor levels on a bar chart. The problem is that R automatically alphabetizes factor levels. I thought this would be fairly straight-forward but...
Should you use daily or monthly returns to estimate volatility? Does garch explain why volatility estimated with daily data tends to be bigger than if it is estimated with monthly data? Previously There are a number of previous posts — with the variance compression tag — that discuss the phenomenon of volatility estimated with daily … Continue reading...
Continuing the summary of last week’s symposium on statistics and data visualization (see part 1 and part 3)… Here I describe Dianne Cook’s discussion of visual inference, and Rob Kass’ talk on statistics in cognitive neuroscience. [Edit: I've added a few … Continue reading →
This week, we look at plotting data using scatterplots. I'll definitely have a post on other ways of plotting data, like boxplots or histograms.
Our data from last week remains the same:
Here are detailed comments on the book. Elsewhere there is a review of the book. How to read R For Dummies In order to learn R you need to do something with it. After you have read a little of the book, find something to do. Mix reading and doing your project. You cannot win … Continue reading...
I have previously written about how we know nothing about code readability and questioned how the information content of expressions might be calculated. Buse and Weimer ran a very interesting experiment that asked subjects to rate short code snippets for readability (somebody please rerun this experiment using professional software developers). I’m interested in measuring how
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
