?ave -- 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 john seers (IFR) > Sent: Friday, November 16, 2007 7:21 AM > To: r-help@r-project.org > Subject: [R] Scaling a column in groups > > > > Hello R people > > I have a column of numeric values that are grouped in blocks > of 25 and to be centered and scaled within each block. (That > is subtract the mean and divide by the standard deviation.) > > Is there a neater way to do this? i.e not using a loop? > > Example looped code: > > testdata<-1:100 > csvalues<-NULL > for (i in 1:(length(testdata)/25)) { > st<-(i-1) * 25 + 1 > sel<-st:(st+24) > selvals<-testdata[sel] > csvalues<-c(csvalues, scale(selvals, scale=sd(selvals))) } > > Thanks for any help. > > > John Seers > > > > > --- > > John Seers > Institute of Food Research > Norwich Research Park > Colney > Norwich > NR4 7UA > > > tel +44 (0)1603 251497 > fax +44 (0)1603 507723 > e-mail [EMAIL PROTECTED] > e-disclaimer at http://www.ifr.ac.uk/edisclaimer/ > > Web sites: > > www.ifr.ac.uk > www.foodandhealthnetwork.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.
