try sqldf:
> x
Sample_no Species Nitrogen Carbon
1 1 Cod 15.2 -19.0
2 2 Haddock 14.8 -20.2
3 3 Cod 15.6 -18.5
4 4 Cod 13.2 -20.1
5 5 Haddock 14.3 -18.8
> require(sqldf)
> sqldf("select Species, avg(Nitrogen) Nitrogen, a
(apologies for any double hits; forgot to reply all...)
Or, you could just go back to basics, and write yourself a general loop that
goes through whatever levels of a variable and gives you back whatever
statistics you want... below is an example where you estimate means for each
level, but you co
Try tapply().
For example:
tapply(data$Nitrogen,factor(data$Species),mean)
For the Nitrogen column, the mean is calculated for each Species. (if the data
frame below is in the object data)
Regards,
Annemarie Eigenhuis
-Original Message-
From: r-help-boun...@r-project.org [mailto:r-he
On Nov 4, 2010, at 8:28 AM, Ramsvatn Silje wrote:
Hello,
I have tried to find this out some other way, but unsuccessful I
have to
try this list.
I assume this should be quite simple.
I have a dataset with 4 columns, "Sample_no", "Species", "Nitrogen",
"Carbon" in csv format. In the specie
4 matches
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