Hello, does anyone know how to take the mean for a subset of observations?
For example, suppose my data looks like this:
OBS NAME SCORE
1 Tom 92
2 Tom 88
3 Tom 56
4 James 85
5 James 75
6 James 32
7 Dawn 56
8 Dawn 91
9 Clara 95
10 Clara 84
Is there a way to get the mean of the SCORE variable by NAME but only when
the number of observations is equal to 3? In other words, is there a way to
get the mean of the SCORE variable for Tom and James, but not for Dawn and
Clara? Thank you.
--
Geoffrey Smith
Visiting Assistant Professor
Department of Finance
W. P. Carey School of Business
Arizona State University
[[alternative HTML version deleted]]
______________________________________________
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.
