I have a data frame that looks something like... Column 1 is an experiment_id, Column 2 is the type of treatment ("control", "full treatment", or "partial treatment"), and Column 3 is a value.
Experiment_id Treament_type Value 12345 "control" 3 12345 "full treatment" 4 12345 "full treatment" 5 12345 "partial treatment" 4 10000 "control" 1 What I want to do is this: For each experiment_id, compute the mean "control" value, the mean "full treatment" value, and the mean "partial treatment" value. Is there an easy way to do this? (Also, for each experiment_id, I then want to find 1) "mean full treatment value" - "mean control value" 2) "mean partial treatment value" - "mean control value".) Thanks! -- View this message in context: http://www.nabble.com/help-with-two-layers-of-factors-tp22851129p22851129.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.