This is a fortune(106) situation (with a little fortune(77) in there as well).
I am unsure what exactly the original poster is wanting to do, but accessing the columns of a data frame (or list) by character strings can be done using [[ ]] rather than $ and should be able to work for this situation (and for data frames you can use matrix subscripting to get columns by name). Try things like: > tmp <- paste( 'x', 1:3, sep='' ) > Data[ , tmp ] > for( i in seq(along=tmp) ) Data[[ tmp[i] ]] Hope this helps, -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare [EMAIL PROTECTED] (801) 408-8111 > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Henrique > Dallazuanna > Sent: Monday, January 07, 2008 10:56 AM > To: Gregory Gentlemen > Cc: [EMAIL PROTECTED] > Subject: Re: [R] evaluating a vector of characters > > Try: > sapply(paste("Data$x", 1:3, sep=""), function(x)eval(parse(text=x))) > > On 07/01/2008, Gregory Gentlemen <[EMAIL PROTECTED]> wrote: > > Dear R users, > > > > I'd like to evaluate a vector of characters. For example, > say I have a data frame called Data including the field names > x1, x2, x3, and I'd like to a list out of paste("Data$x", > 1:3, sep=""). How can I get list to evaluate paste("Data$x", > 1:3, sep="") as an R object rather than a string? > > > > Thanks in advance for you assistance. > > Gregory > > > > > > --------------------------------- > > > > [[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. > > > > > -- > Henrique Dallazuanna > Curitiba-Paraná-Brasil > 25° 25' 40" S 49° 16' 22" O > > ______________________________________________ > 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.
