On Sun, Nov 16, 2008 at 9:56 PM, Christian Arnold <[EMAIL PROTECTED]> wrote: > Hello R-Community, > > I am pretty new to R and I am fascinated what R can do! I am doing > phylogenetic analysis in R, and my current project includes two problems > that I am unable to solve, unfortunately. I am hoping that someone knows an > easy, and R-typical solution, any help would be appreciated. Specifically, I > have the following two problems: > > 1) I am reading in all the files from a directory using file_list <- > list.files(). It works, of course, however, I want to restrict file_list to > files that end with ".nex". Thus, I want to remove some files from this > list. I read that I can do something like file_list <- file_list[condition]. > I do not know how to express my condition here, unfortunately. Pseudo code > would be something like file_list <- file_list[ends with ".nex"]
Maybe you could use dir() instead - see particularly the pattern argument. > 2) A slightly more complicated problem, at least I think that. I have two > lists, list1 and list2. list1 contains some elements (characters such as > "species1"). list2 contains also species names, including all of list1, but > also species that are not part of list1. I need a way to create a list that > contains ONLY those elements that are in list2, but not in list1. > For example: list1 = c("s1","s3","s4","s7"), list2 = > c("s1","s2","s3","s4","s5","s6","s7"), now I need a way to create the list > list3 = c("s2","s5","s6"). Any ideas? I am not able to find the appropriate > function... Have a look at setdiff. Hadley -- http://had.co.nz/ ______________________________________________ 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.