[This article was first published on DiffusePrioR » R, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here)
Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.
Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.
There are many occasions in my research when I want to create a within group index for a data frame. For example, with demographic data for siblings one might want to create a birth order index.
The below illustrates a simple example of how one can create such an index in R.
set.seed(123)
# two families/groups 1 and 2
# with random ages
data = data.frame(group = c(rep(1,5),rep(2,5)), age = rpois(10,10))
# birth order
# use rank function with negative age for descending order
data$bo = unlist(by(data, data$group,
function(x) rank(-x$age, ties.method = "first")))
To leave a comment for the author, please follow the link and comment on their blog: DiffusePrioR » R.
R-bloggers.com offers daily e-mail updates about R news and tutorials about learning R and many other topics. Click here if you're looking to post or find an R/data-science job.
Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.