That is what I read the other day. For calculation of descriptive statistics, values below the LLOQ (lower limit of quantification) were set to.... Then I wondered, wasn't there a trick in JAGS to incorporate the presence of missing data while es...

After 8 years of using R, today I finally become a contributor to the community and released my first package, FAOSTAT.The package is designed to provide user with direct access to the FAOSTAT data base via R and to support the...

Using R and ggplot2 to draw a scatterplot with the two marginal boxplotsDrawing a scatterplot with the marginal boxplots (or marginal histograms or marginal density plots) has always been a bit tricky (well for me anyway). The approach I take here is, first, to draw the three separate plots using ggplot2:the scatterplot;the horizontal boxplot to appear in the...

With only 24 hours remaining in the 2012 NFL season, this is a good time to review how the league's QBs performed during the regular season using performance data from KFFL and the heat mapping capabilities of R. #scale data to mean=0, sd=1 and convert to matrix QBscaled <- as.matrix(scale(QB2012)) #create heatmap and don't reorder

A big problem in reproducible research is that software changes. The code you used to do a piece of research may depend on a specific version of software that has since been changed. This is an annoying problem in R because install.packages only installs the most recent version of a package. It can be tedious to collect the old...

Or, The 2010 Mariners: How Bad Were They?In earlier posts, I used the statistical software R to plot the trends in league average run scoring since 1901. This was the first step to answering other questions I had on my mind:How poor was the offensive performance of the 2010 Seattle Mariners?Are they showing any signs...

I spent a portion of today trying to convince a colleague that there are times when the data.table package is faster than traditional methods in R. It took a few of the tests below to prove the point. Generate a data.frame of characters and numbers for easy plotting. df <- data.frame(letters = as.character(sample(letters, 1e+08, replace = TRUE)), ...

Consider the following time series, What does it look like ? I know, this is a stupid game, but I keep using it in my time series courses. It does look like a random walk, doesn’t it ? If we use Philipps-Perron test, yes, it does, > PP.test(x) Phillips-Perron Unit Root Test data: x Dickey-Fuller = -2.2421, Truncation lag parameter = 6,...

Another site pops up with open code for analyzing public survey data: http://www.asdfree.com/ It will be interesting to see whether this gets used by the general public--given the growing trend of data journalism and so forth--versus academics. It is...