Thanks a lot, Petr! This works perfect! myList was actually a list of data.frame, and the command line initially choked. But once I converted it to matrix, it worked like a charm:
apply(do.call(rbind, lapply(lapply(myList, as.matrix), c)), 2, t.test) Thanks, Gang On Mon, Oct 6, 2008 at 9:42 AM, Petr PIKAL <[EMAIL PROTECTED]> wrote: > Hi > > maybe not an answer you like but > > apply(do.call(rbind, lapply(myList, c)), 2, t.test) > > shall give you desired results > > Regards > Petr > > > [EMAIL PROTECTED] napsal dne 02.10.2008 23:25:23: > >> I appreciate your suggestion. The example I provided was fabricated >> because I was only focusing on the programming perspective on how to >> deal with such a data structure, not real statistical issues. Do you >> mind elaborating a little more why that would not be appreciate? I >> know I can do it with a couple of loops, but I still appreciate >> suggestions on how to write a line or two to run t-tests on such a >> data structure. >> >> Thanks, >> Gang >> >> >> On Thu, Oct 2, 2008 at 5:11 PM, Bert Gunter <[EMAIL PROTECTED]> > wrote: >> > I am sure you will get helpful answers. I am almost as sure that you >> > shouldn't be doing this. I suggest you consult with your local > statistician. >> > >> > -- Bert Gunter >> > >> > -----Original Message----- >> > From: [EMAIL PROTECTED] [ > mailto:[EMAIL PROTECTED] On >> > Behalf Of Gang Chen >> > Sent: Thursday, October 02, 2008 11:24 AM >> > To: [EMAIL PROTECTED] >> > Subject: [R] t.test() on a list >> > >> > I have a list, myList, with each of its 9 components being a 15X15 >> > matrix. I want to run a t-test across the list for each component in >> > the matrix. For example, the first t-test is on myList[[1]][1, 1], >> > myList[[2]][1, 1], ..., myList[[9]][1, 1]; and there are totally 15X15 >> > t-tests. How can I run these t-tests in a simple way? >> > >> > TIA, >> > Gang ______________________________________________ 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.