The tidyverse and, in particular, dplyr, provides functions to select columns from a data frame. There are three scoped functions available: select_all, select_if and select_at. In this post, we’ll look at a particular application of select_if, i.e., capturing the names of numeric variables. A ...

When evaluating the sampling variability of different statistics, I’ll often use the bootstrap procedure to resample my data, compute the statistic on each sample, and look at the distribution of the statistic over several bootstrap samples. In principle, the bootstrap is straightforward to do. However, if you have correlated ...

Well, here’s what I was dealing with: Exemplar Excel file from collaborator Notice that we have 3 header rows, first with patient IDs, second with spine region, and third with variable names (A and B, to protect the innocent). Goal A dataset that, for each patient and each angle gives ...

I was recently asked to do a panel of grouped boxplots of a continuous variable, with each panel representing a categorical grouping variable. This seems easy enough with ggplot2 and the facet_wrap function, but then my collaborator wanted p-values on the graphs! This post is my approach to the ...