Conversion to factor may happen (and often does) when you read in data with read.table(). So one solution may be reading in the same data again in a slightly different way:
read.table(file="mydatafile", as.is=TRUE) # see also ?read.table You can also specify a class to each column of the data you're about to read in: read.table(****, colClasses=c("numeric", "factor", "character", "my.funny.class")) Ad take a look at http://cran.r-project.org/doc/FAQ/R-FAQ.html p. 7.10 for the right answer -- in any case, don't use as.numeric(x)! Kenn On Thu, Jun 12, 2008 at 9:24 AM, Qman Fin <[EMAIL PROTECTED]> wrote: > Hi all, > > I have some data x, which are actualy consisted of numerical enties. But > the > class of this matrix is set to be "factor" by someone else. I used > "class(x)", it turns out to be "factor". So I can not calculate them. > > How can I turn them into numerical data so that I can apply math operations > on them? Thanks a lot for your help. > > Selina > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > [[alternative HTML version deleted]] ______________________________________________ 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.