Hi all,
I am looking to create a rank variable based on a continuous variable
for subsets of the data. For example, for an R integrated data set
about US states this is how a loop could create what I want:
### Example with loop
data <- cbind(state.region,as.data.frame(state.x77))[,1:2] #
choosing a subset of the data
data <- data[order(data$state.region, 1/data$Population),] #
ordering the data
regions <- levels(data$state.region)
temp <- NULL
ranks <- NULL
for (i in 1:length(regions)){
temp <- rev(rank(data[data$state.region==regions[i],"Population"]))
ranks <- c(ranks,temp)
}
data$rank <- ranks
data
where data$rank is the rank of the state by population within a region.
However, using loops is slow and cumbersome. I have a fairly large
data set with many subgroups and the loop runs a long time. Can
someone suggest a way to create such rank variable for subsets without
using a loop?
Thank you,
Thomas
______________________________________________
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.
