I was preparing a data analysis assignment for one of my classes, and decided I needed an example for my students. Similar to what I’m asking of my students, I wanted to use public employee salary data from the the Texas Tribune Government Salaries Explorer. After a few moments’ thought* , I hit upon theContinue reading “Non-tenure track salaries”

# Category Archives: R tips and tutorials

## Data to Viz

For data analysts using R, this is huge. Find out how to generate the graph you need for the data you have with just a few clicks. Yes, you’ll find some fine print explaining that the site is not comprehensive. BUT, it still has a trove of graph types and accompanying R and python codeContinue reading “Data to Viz”

## R Tutorial: the non-linear equation solver

Need a numerical solution to simultaneous non-linear equations? The nleqslv package is just what you’re looking for! The coding required is minimal; just define the equations you want solved in a function, set some initial values, and let ‘er rip. Here’s an example that uses the method of moments to estimate the parameters of aContinue reading “R Tutorial: the non-linear equation solver”

## R Tutorial: Correlation

Fisher’s iris dataset is the basis for this extended example in the calculation and visualization of correlations. The ggpairs() function gives an impressive coded scatterplot matrix. And an old friend makes a last-minute cameo appearance. Update: Dirk Eddelbuettel just released tint 0.0.3 (tint is not Tufte) with some nifty examples. I wanted to try itContinue reading “R Tutorial: Correlation”

## R Tutorial: A Bayesian Estimate of Proportion

This is an old chestnut in Bayesian statistics, using the conjugate beta prior to find a beta posterior distribution for a proportion. If you’re unfamiliar with the calculation of the posterior distribution, there’s a link in the tutorial.

## R Tutorial: Teasing Out a Markov Chain

Azzalini and Bowman’s Old Faithful geyser data provides fodder for a lot of data exploration in R (scatterplots, ggplot2, simple regression, kmeans clustering, and Markov chain estimation). All the really interesting stuff in the tutorial happens if you click through to Analysis > Models > Standardized Cluster Model. (The standardized clustering approach is not givenContinue reading “R Tutorial: Teasing Out a Markov Chain”

## Beginning: R Tutorials

After a long, slow start, R is catching on with statisticians and (some) scientists at UTSA. The Biology Department has asked that I use R in teaching biostatistics, and many of the courses for statistics majors are using R rather than SAS (a UTSA tradition). Students have not been idle; the statistics club has askedContinue reading “Beginning: R Tutorials”