Hello, I would like to take the mean of a column from a data frame and then
bind the mean back to the data frame.  I can do this using the following
lines of code, but I am looking for a more elegant solution.  Thank you very
much.  Geoff

name <- c('Frank','Frank','Frank','Tony','Tony','Tony','Ed','Ed','Ed');
year <- c(2004,2005,2006,2004,2005,2006,2004,2005,2006);
sale <- c(56,45,55,65,68,70,45,67,23);

data <- data.frame(name=name, year=year, sale=sale);
data;

#is there a more elegant way to add a column of means for sale by name than
what I did below?;

mean <- data.frame(aggregate(data$sale, list(data$name), mean));
colnames(mean) <- c('name','mean');
mean;

data <- merge(data, mean);
data;

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