pmatch() facilitates a very simple solution: #Data IA <- factor(c(1,2,2,3,3,4,3,5,5)) FixTime <- c(200,350,500,600,700,850,1200,1350,1500)
#First occurrence of each level first. <- pmatch(levels(IA),IA) #Use first occurrence to subscript a vector or data frame FixTime[first.] A simple way to apply pmatch across unique combinations of levels of several factors is to create a new composite factor with paste() and factor(), then proceed as above. -- View this message in context: http://www.nabble.com/Calculating-First-Occurance-by-a-factor-tp22789964p22834451.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.
