sort.data.frame

August 15, 2014
By

(This article was first published on Mark van der Loo, and kindly contributed to R-bloggers)

I came accross this post on SO, where several solutions to sorting data.frames are presented. It must have been solved a million times, but here's a solution I like to use. It benefits from the fact that sort is an S3 generic.

sort.data.frame <- function(x, decreasing=FALSE, by=1, ... ){
  f <- function(...) order(...,decreasing=decreasing)
  i <- do.call(f,x[by])
  x[i,,drop=FALSE]
}

It sorts on the first column by default, but you may use any vector of valid column indices. Here are some examples.

sort(iris, by="Sepal.Length")
sort(iris, by=c("Species","Sepal.Length"))
sort(iris, by=1:2)
sort(iris, by="Sepal.Length",decreasing=TRUE)

To leave a comment for the author, please follow the link and comment on his blog: Mark van der Loo.

R-bloggers.com offers daily e-mail updates about R news and tutorials on topics such as: visualization (ggplot2, Boxplots, maps, animation), programming (RStudio, Sweave, LaTeX, SQL, Eclipse, git, hadoop, Web Scraping) statistics (regression, PCA, time series, trading) and more...



If you got this far, why not subscribe for updates from the site? Choose your flavor: e-mail, twitter, RSS, or facebook...

Comments are closed.