On Thu, 2 Sep 2021, Andrew Simmons wrote:
You could use 'split' to create a list of data frames, and then apply a function to each to get the means and sds.cols <- "cfs" # add more as necessary S <- split(discharge[cols], format(discharge$sampdate, format = "%Y-%m")) means <- do.call("rbind", lapply(S, colMeans, na.rm = TRUE)) sds <- do.call("rbind", lapply(S, function(xx) sapply(xx, sd, na.rm = TRUE)))
Andrew, Thank you for the valuable lesson. This is new to me and I know I'll have use for it in the future, too. Much appreciated! Stay well, Rich ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
