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Message-ID: <98782.49656.qm@web38302.mail.mud.yahoo.com>
Date: 2009-11-03T13:28:11Z
From: FMH
Subject: tapply function

Hi,

I tried to use tapply function to find the mean of the data?in each group as the following command, but the result are NA, as there are several missing values in each group.

tapply(data,group,mean)

Could someone please advice me the way to ?ignore the missing data in order for the fucntion to run successfully?

Thanks

Fir