I have a data frame called df which has about 100 columns but thousands of rows. I set D the index of df$D and M to be the index of df$M. When I run the following loop as it is vs. df[,D] and df[,M] replaced with df$D and df$M there is a real big time difference in completion (with the latter being significantly faster). Is there an easy reason why and how I could speed up access?
for (m in 1:12) { for (d in 1:31) { filter1<-((df[,D]==d) & (df[,M]==m)) if(sum(filter1)>0) { ctr<-ctr+1 dates[ctr]<-paste(as.character(d),as.character(m)) } } } Thanks... [[alternative HTML version deleted]] ______________________________________________ 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.