Hi Jim, Using ?lapply with ?colMeans should do the trick. Here is a little sample:
eg <- list(mtcars, mtcars) # mtcars data frame twice in a list resultsmean <- lapply(eg, colMeans) # calculate column means for each element of "eg" resultsmean # show the results Hope this helps, Josh On Sun, Apr 10, 2011 at 8:27 AM, Maas James Dr (MED) <j.m...@uea.ac.uk> wrote: > Long story short, I have a big iterative procedure that produces a long list > of data.frames such as the one called > "results" here. Is there an easy way to produce a similar list of > data.frames comprised of the mean of each of the > columns in results, such that it ends up like the one I've shown in > "resultsmean" below? > > I've tried apply and lapply, still not got the correct arguments. As usual, > TIA. > > Jim > >> results > [[1]] > name LOR23 BIA23 MSE23 H0R23 > 1 0.2111122 -1.012228 -0.095937 0.035650 1.00 > 2 0.2111122 -0.836300 0.079991 0.042322 0.75 > 3 0.2111122 -0.518631 0.397659 0.214593 0.50 > > > [[2]] > name LOR23 BIA23 MSE23 H0R23 > 1 0.2211122 -0.724630 0.191660 0.051308 1 > 2 0.2211122 -0.781812 0.134478 0.033872 1 > 3 0.2211122 -0.522109 0.394181 0.164628 0.75 > > > would like > >> resultsmean > [[1]] > name LOR23 BIA23 MSE23 H0R23 > 1 0.2111122 -0.78333 0.12734 0.097160 0.75 > > [[2]] > name LOR23 BIA23 MSE23 H0R23 > 1 0.2211122 -0.67566 0.2400 0.08266 0.916 > > =============================== > Dr. Jim Maas > University of East Anglia > > ______________________________________________ > 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. > -- Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles http://www.joshuawiley.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.
