Hi, I'm essentially wanting to calculate intra- and inter-observer variabilities for the first principal component of an optic disc shape measure of a sample of individuals, so from what I can work out I need to work out an intraclass correlation coefficient(s).
For the intra-data, I have 2 measurements taken on each individual by the same observer. For the inter-data, 2 observers have taken one measurement each on the sample. I've found the 'icc' function in the {psy} package, but am not sure how I'd perform the intra- calculation as the data argument is an 'n*p matrix or dataframe, n subjects p raters'. Would I just substitute the replica for the rater? Hope this makes sense - still learning about it all. Thank you. Paul -- View this message in context: http://www.nabble.com/How-to-do-ICC-tp21849168p21849168.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.