Bootsrap Confidence Intervals, Stratified Bootstrap

April 20, 2011

(This article was first published on theBioBucket*, and kindly contributed to R-bloggers)

 Here's a worked example for comparing group averages with bootstrap confidence intervals and allowing for different subsample sizes by calling the strata argument within the bootstrap function.
The data is set up analogous to an before-after impact experiment conducted on plots across four different successional stages. Similarity was calculated for plot's composition before and after an impact. One hypothesis was that certain stages would show higher / smaller average similarities, that is, a higher / lower impact on composition. As plots within stages were situated within different subsites and the nr. of replicates was unbalanced, this had to be allowed for by use of the "strata" argument in the call:

Read more »

To leave a comment for the author, please follow the link and comment on their blog: theBioBucket*. offers daily e-mail updates about R news and tutorials on topics such as: Data science, Big Data, R jobs, 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...

Tags: , , , , , , , ,

Comments are closed.

Search R-bloggers


Never miss an update!
Subscribe to R-bloggers to receive
e-mails with the latest R posts.
(You will not see this message again.)

Click here to close (This popup will not appear again)