Hello all, This is one of those "Is there a better way to do this questions". Say I have a dataframe (df) with a grouping variable (z). This is my base data. Now I know that there is a higher order level of grouping that exist for my group variable. So what I want to do is create a new column that express that higher order level of grouping based on values in the sub-group (z in this case). In the past I have used ifelse() but this tends to get fairly redundant and messy with a large amount of sub-groupings (z). I've created a sample dataset below. Can anyone recommend a better way of achieving what I am currently achieving with ifelse()? A long series of ifelse statements makes me think that there is something better for this.
## Dataframe creation df <- data.frame(x=runif(36, 0, 120), y=runif(36, 0, 120), z=factor(c("A1","A1","A2","A2","B1","B1","B2","B2","C1","C","C2","C2")) ) ## Current method is grouping df$Big.Group <- with(df, ifelse(df$z=="A1","A", ifelse(df$z=="A2","A", ifelse(df$z=="B1", "B", ifelse(df$z=="B2", "B", "C"))))) So any suggestions? Thanks in advance! Sam ______________________________________________ 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.