try something like the following: lis1 <- c(lapply(1:10, rnorm, n = 10)) lis2 <- c(lapply(1:10, rnorm, n = 10)) lis1[[5]] <- lis2[[8]] <- numeric(0) ############################################ ind <- sapply(lis1, length) > 0 & sapply(lis2, length) > 0 lis1 <- lis1[ind] lis2 <- lis2[ind]
mapply(function(x, y) wilcox.test(x, y)$p.value, lis1, lis2) I hope it helps. Best, Dimitris ---- Dimitris Rizopoulos Ph.D. Student Biostatistical Centre School of Public Health Catholic University of Leuven Address: Kapucijnenvoer 35, Leuven, Belgium Tel: +32/(0)16/336899 Fax: +32/(0)16/337015 Web: http://med.kuleuven.be/biostat/ http://www.student.kuleuven.be/~m0390867/dimitris.htm Quoting "Raj, Towfique" <[EMAIL PROTECTED]>: > Dear all, > I'm a newbie to R and I would really apperciate any help with the following: > > I have two lists, l1 and l2: > > l1: > $"A*0101" > [1] 0.076 0.109 0.155 0.077 0.09 0 0 0.073 > [9] 0.33 0.0034 0.0053 > > > $"A*0247" > [1] 0 0 0.5 .004 0 0 0 > > $"A*0248" > [1] 0 0 0.3 0 0.06 > > .... > > l2: > > $"A*1101" > [1] 0.17 0.24 0.097 0.075 0.067 > > $"A*0247" > numeric(0) > > $"A*0248" > [1] 0.031 > > .... > > Basically, what I want to do is run wilcox.test() on each entry pair > in the list. > > 1) I want to loop through the list to run wilcox.test for each entry > of the list. How would I do that? mapply()? > > wilcox.test(l0[[1]],l1[[1]]) for the first one and so on.... > > 2) I want to exclude the list entry which has no values (i.e. A*0247). > > 3) Finally, I only want the to see the 'p-value' for each list names. > The output I want capture is only the 'p-value' object from > wilcox.test. > > name p-value > A*0101 0.8329 > .... .... > > I'm grateful for any help, or any pointers to a good online tutorial. > > Thanks a lot in advance, > > -T. > > ______________________________________________ > R-help@stat.math.ethz.ch 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. > > Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm ______________________________________________ R-help@stat.math.ethz.ch 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.
