Hi,
I have a data.frame that looks like this: Subject <- c(rep(1,4), rep(2,4), rep(3,4)) y <- rnorm(12, 3, 2) gender <- c(rep("w",4), rep("m",4), rep("w",4)) comment <- c(rep("comment A",4), rep("comment B",4), rep("comment C",4)) data <- data.frame(Subject,y,gender,comment) data Subject y gender comment 1 1 2.86495339 w comment A 2 1 3.33758993 w comment A 3 1 7.00301094 w comment A 4 1 3.81585998 w comment A 5 2 2.50300460 m comment B 6 2 4.93830489 m comment B 7 2 5.08184289 m comment B 8 2 4.00552691 m comment B 9 3 3.16131181 w comment C 10 3 4.61620021 w comment C 11 3 3.68288799 w comment C 12 3 -0.05049953 w comment C So I have multiple lines for one subject because of a repeated measurement of variable y (the rest of the variables stay the same, like gender). Now I would like to transform this data.frame in two ways: 1. a aggregated form, where I only have one row left for each subject - for numerical variables within the data.frame (like y) a mean should be calculated. 2. a restructured form, where I only have one row for each subject, but four different y-columns (y1, y2, y3, y4). What is the easiest way to do this? Are there any functions who do this kind of data-frame rearranging in one step? ______________________________________________ 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.