Cat <- c('a','a','a','b','b','b','a','a','b') C1 <- ifelse(Cat == 'a', -1, 1)
------------------------------------------------------------------------ ---- ir. Thierry Onkelinx Instituut voor natuur- en bosonderzoek / Research Institute for Nature and Forest Cel biometrie, methodologie en kwaliteitszorg / Section biometrics, methodology and quality assurance Gaverstraat 4 9500 Geraardsbergen Belgium tel. + 32 54/436 185 [EMAIL PROTECTED] www.inbo.be Do not put your faith in what statistics say until you have carefully considered what they do not say. ~William W. Watt A statistical analysis, properly conducted, is a delicate dissection of uncertainties, a surgery of suppositions. ~M.J.Moroney > -----Oorspronkelijk bericht----- > Van: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Namens Keith Alan > Chamberlain > Verzonden: woensdag 4 juli 2007 15:45 > Aan: r-help@stat.math.ethz.ch > Onderwerp: [R] A More efficient method? > > Dear Rhelpers, > > Is there a faster way than below to set a vector based on > values from another vector? I'd like to call a pre-existing > function for this, but one which can also handle an > arbitrarily large number of categories. Any ideas? > > Cat=c('a','a','a','b','b','b','a','a','b') # Categorical variable > C1=vector(length=length(Cat)) # New vector for numeric values > > # Cycle through each column and set C1 to corresponding value of Cat. > for(i in 1:length(C1)){ > if(Cat[i]=='a') C1[i]=-1 else C1[i]=1 > } > > C1 > [1] -1 -1 -1 1 1 1 -1 -1 1 > Cat > [1] "a" "a" "a" "b" "b" "b" "a" "a" "b" > > Sincerely, > KeithC. > Psych Undergrad, CU Boulder (US) > RE McNair Scholar > > ______________________________________________ > R-help@stat.math.ethz.ch 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@stat.math.ethz.ch 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.