Hi Henrik, Thanks for your reply.
I am not (yet) convinced, though. The help page for read.table mentions named colClasses and if I specify colClasses for not all columns, the names are taken into account: --8<---------------cut here---------------start------------->8--- kkk <- c("a\tb", "3.14\tx") str(read.table(textConnection(kkk), sep="\t", header = TRUE)) str(read.table(textConnection(kkk), sep="\t", header = TRUE, colClasses=c(b="character"))) --8<---------------cut here---------------end--------------->8--- What am I missing? Best, Andreas On 09/07/2015 02:21, Henrik Bengtsson wrote: > read.table() does not make use of names(colClasses) - only its values. > Because of this, ordering is critical, as you noted. It shouldn't be > too hard to add support for a named `colClasses` argument of > utils::read.table(), but someone needs to convince the R core team > that this is a good idea. > > As an alternative, see R.filesets::readDataFrame() for a > read.table()-like function that matches names(colClasses) to column > names, if they exists. > > /Henrik > (author of R.filesets) > > On Wed, Jul 8, 2015 at 5:41 PM, Andreas Leha > <andreas.l...@med.uni-goettingen.de> wrote: >> Hi all, >> >> Apparently, the colClasses argument to read.table needs to be in the >> order of the columns *even when it is named*. Why is that? And where >> would I find it in the documentation? >> >> Here is a MWE: >> >> --8<---------------cut here---------------start------------->8--- >> kkk <- c("a\tb", >> "3.14\tx") >> read.table(textConnection(kkk), >> sep="\t", >> header = TRUE) >> >> cclasses=c(b="character", >> a="numeric") >> >> read.table(textConnection(kkk), >> sep="\t", >> header = TRUE, >> colClasses = cclasses) ## <--- error >> >> read.table(textConnection(kkk), >> sep="\t", >> header = TRUE, >> colClasses = cclasses[order(names(cclasses))]) >> --8<---------------cut here---------------end--------------->8--- >> >> >> Thanks, >> Andreas >> >> ______________________________________________ >> 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.