[R] aggregate() nlevels()

[Tord Snall]

Dear all,

I try to calculate the number of occurring levels, per ObjektID, of
cpy.busk$TradArt,
but this line returns the TOTAL number of levels occurring in
cpy.busk$TradArt for each ObjektID. 

This was difficult to say in English! Did you get it?

Is there any function for doing what I want. I have tried searching the
archives without success.

buskartant<- aggregate(list(buskartant = cpy.busk$TradArt), list(ObjektID =
cpy.busk$ObjektID), nlevels)


Thanks in advance!

Sincerely,
Tord

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Tord Snäll
Avd. f växtekologi, Evolutionsbiologiskt centrum, Uppsala universitet
Dept. of Plant Ecology, Evolutionary Biology Centre, Uppsala University
Villavägen 14			
SE-752 36 Uppsala, Sweden
Tel: 018-471 28 82 (int +46 18 471 28 82) (work)
Tel: 018-25 71 33 (int +46 18 25 71 33) (home)
Fax: 018-55 34 19 (int +46 18 55 34 19) (work)
E-mail: Tord.Snall at ebc.uu.se
Check this: http://www.vaxtbio.uu.se/resfold/snall.htm!
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