Dear all, I am trying to use 'merge' within a loop, however, I receive an error relating to the 'by' argument of the command, as follows:
> merge_year <- 1986 > > for (i in 1:10) { # Number of file pairs + assign(paste("merged_arunfek_", merge_year, sep=""), merge(x=paste("arunoff_",start_arunoff, sep=""), y=paste("fekete_", start_fekete, sep=""), by=c("Latitude", "Longitude"), sort=FALSE)) + attach(paste("merged_arunfek_", merge_year)) + merge_year = merge_year+1 + } Error in fix.by(by.x, x) : 'by' must specify valid column(s) However, as far as I can tell, the column names (as stated in the above code) appear to be valid: > colnames(arun_1986) [1] "Latitude" "Longitude" "Sim_1986" > colnames(fekete_1986) [1] "Latitude" "Longitude" "X1986" I'm trying to merge based on both the Latitude and Longitude column and have used by=c("name_x", "name_y") before without too many problems. Any suggestions would be gratefully received. Many thanks, Steve ______________________________________________ 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.