Hello,
Try the following.
# make up some data
dat <- data.frame(values = rnorm(100), experiment = sample(10, 100,
TRUE), composite = sample(17, 100, TRUE))
aggregate(values ~ experiment + composite, data = dat, FUN = mean)
Hope this helps,
Rui Barradas
Em 11-01-2013 23:26, li li escreveu:
Dear all,
I have a data frame where there are three variables: values, experiment,
composite.
Values are numerical values. There are 10 levels for the experiment. Within
each level of experiment,
there are 17 levels of composite.
I want to find mean for each combination of levels of the experiment and
the levels of composite.
Can anyone give some help here.
Thank you, Hanna
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