--- On Tue, 5/4/10, Petr PIKAL <petr.pi...@precheza.cz> wrote:
> From: Petr PIKAL <petr.pi...@precheza.cz> > Subject: Re: [R] / Operator not meaningful for factors > To: "John Kane" <jrkrid...@yahoo.ca> > Cc: r-help@r-project.org, "vincent.deluard" <vincent.delu...@trimtabs.com> > Received: Tuesday, May 4, 2010, 3:38 AM > Hi > > r-help-boun...@r-project.org > napsal dne 04.05.2010 00:50:00: > > > I think that you are correct. R has the > annoying habit of converting > > character data to factors when you don't want it to > while it is > importing > > data. This is because the in the option > "stringsAsFactors" is set to > TRUE for > > some weird historical reasons. > > It is a matter of opinion. I consider it quite useful > feature. If I see by > > str(some.data) or summary(data0 that numeric columns are > factors I know > something is wrong with input. I'm not denying that it can be useful but IIRC from a discussion a couple of years ago, it was a fairly arbitary decision. On the other hand it can be very annoying when one has some kinds of data. > > and when I want to use ggplot, xyplot or just plot my data > with different > colours/sizes/pchs/.... it is quite easy to use > as.numeric(my.factor) to > get numeric representation of levels. > > Finally you can easily change labels, concatenate levels > and so on. > > Just my 2 cents. > > Regards > Petr > > > > > > > Try the command str(insert name of data) and see what > happens. It > should show > > you which columns of data are being treated as > factors. > > > > You can convert the back to character or to > numeric. See the FAQ Part 7 > "How > > do I convert factors to numeric? " or you can use the > String as options > > command in the read.table to FALSE > > > > Something like this should work, I think, but it's not > tested > > read.table("C:/rdata/trees.csv", > stringsAsFactors=FALSE) > > > > > > > > > > > > --- On Mon, 5/3/10, vincent.deluard <vincent.delu...@trimtabs.com> > > wrote: > > > > > From: vincent.deluard <vincent.delu...@trimtabs.com> > > > Subject: Re: [R] / Operator not meaningful for > factors > > > To: r-help@r-project.org > > > Received: Monday, May 3, 2010, 6:22 PM > > > > > > Hi there, > > > > > > This will sound very stupid because I just > started using R > > > but I see you had > > > similar problems. > > > > > > I just loaded a very large dataset (2950*6602) > from csv > > > into R. The format > > > is ticker=row, date=column. > > > Every time I want to compute basic operations, R > returns > > > "In Ops.factor: not > > > meaningful for factors" > > > > > > I believe it is because R does not read the data > as numbers > > > but I am not > > > sure. Can anybody help? > > > > > > Thanks! > > > -- > > > View this message in context: > http://r.789695.n4.nabble.com/Operator-not- > > meaningful-for-factors-tp791563p2124697.html > > > Sent from the R help mailing list archive at > Nabble.com. > > > > > > ______________________________________________ > > > 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. > > > > > > > ______________________________________________ > > 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. > > ______________________________________________ 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.