You *might* be able to get them from the raw file... First, I don't quite know what "colnames" of an .RData file means. "colnames" are the column names of a matrix (or data frame), so I'll assume your .RData file contains exactly one data frame and you want to column names of it.
So let's create one of those: mydataframe = data.frame(mylongnamehere=runif(3), anotherlongname=runif(3), z=runif(3), y=runif(3), aasdkjhasdkjhaskdj=runif(3)) save(mydataframe, file="./test.RData") Now I'm going to use some Unix utilities to see if there's any identifiable strings in the file. .RData files are by default compressed using `gzip`, so I'll `gunzip` them and pipe it into `strings`: $ gunzip -c test.RData | strings -t d 0 RDX2 35 mydataframe 230 names 251 mylongnamehere 273 anotherlongname 314 aasdkjhasdkjhaskdj 347 row.names 389 class 410 data.frame - thats found the object name (mydataframe) and most of the column names except the short ones, which are too short for `strings` to recognise. But if your names are long enough (4 or more chars, I think) they'll show up. Of course you'll have to filter them out from all the other string output, but they should all appear shortly after the word "names", since the colnames of a data frame are the "names" attribute of the data. If you don't have a Unix or Mac machine handy you can get these utilities on Windows via Cygwin but that's another story... Barry On Wed, Mar 16, 2016 at 3:59 PM, Lida Zeighami <lid.z...@gmail.com> wrote: > Hi, > I have a huge .RData file and I need just to get the colnames of it. so is > there any way to reach the column names without loading or reading the > whole file? > Since the file is so big and I need to repeat this process several times, > so it takes so long to load the file first and then take the colnames! > > Thanks > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.