[R] Mean Help

[R. Michael Weylandt]

Many forms, but I'll recommend this one this time around:

aggregate(height ~ eyes, DATA, mean)

See ?aggregate for an explanation of what aggregate() does and
?formula for an explanation of the tilde syntax.

Note that this assumes your column names are "height" and "eyes."
Adjust as needed.

Michael

On Wed, Oct 31, 2012 at 1:18 PM, Hard Core <gioxc at hotmail.it> wrote:
> I have a dataframe.
> Let's suppose that i have two columns. The first one contains height, the
> second one contains eye color that can be Green, Blue or Brown.
> I want to calculate the aritmetic mean of the height only for those people
> who have Blue eyes. How can I do it?
> Thank you for your availability.
>
>
>
>
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