Is the whole thing a data frame? Then any multi-column subset is also a data frame. Try adding a as.matrix() wrapper in the definition of rF.
Michael On Nov 15, 2011, at 3:14 PM, "Rob Griffin" <robgriffin...@hotmail.com> wrote: > Error in cor(x[a], x[b], use = "complete.obs") : 'x' must be numeric > > This is strange, it works on your example (and you've understood what I'm > trying to do perfectly), but then when I use it on the original data it comes > up with the error above > I've checked str() and the columns are all numeric > > ??? > > -----Original Message----- From: Joshua Wiley > Sent: Tuesday, November 15, 2011 7:14 PM > To: robgriffin247 > Cc: r-help@r-project.org > Subject: Re: [R] correlations between columns for each row > > Hi Rob, > > Here is one approach: > > > ## define a function that does the calculations > ## (the covariance of two vectors divided by the square root of > ## the products of their variances is just a correlation) > rF <- function(x, a, b) cor(x[a], x[b], use = "complete.obs") > > set.seed(1) > bigdata <- matrix(rnorm(271 * 13890), ncol = 271) > > results <- apply(bigdata, 1, FUN = rF, a = 174:213, b = 214:253) > > ## combine > bigdata <- cbind(bigdata, iecorr = results) > > Hope this helps, > > Josh > > On Tue, Nov 15, 2011 at 8:42 AM, robgriffin247 > <robgriffin...@hotmail.com> wrote: >> Just as an update on this problem: >> I have managed to get the variance for the selected columns >> >> Now all I need is the covariance between these 2 selections - >> the two target columns are and the aim is that a new column contain a >> covariance value between these on each row: >> >> maindata[,c(174:213)] and maindata[,c(214:253] >> >> I've played around with all sorts of apply (and derivatives of apply) and in >> various different setups so I think I'm close but I feel like I'm chasing my >> tail here! >> >> -- >> View this message in context: >> http://r.789695.n4.nabble.com/correlations-between-columns-for-each-row-tp4039193p4073208.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. >> > > > > -- > Joshua Wiley > Ph.D. Student, Health Psychology > Programmer Analyst II, ATS Statistical Consulting Group > University of California, Los Angeles > https://joshuawiley.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.
