[R] Remove specific rows in a matrix/data.frame

[Eik Vettorazzi]

Hi,
just put it in the formula:

aggregate(Number ~ Letter+Test,data=dtf,max)

cheers

Am 13.10.2011 19:30, schrieb syrvn:
> Hello again,
> 
> 	
> dtf<-read.table(textConnection("Letter Test Number 
> 							a b 1 
> 							a b 1 
> 							b b 1 
> 							b b 0 
> 							c b 0 
> 							c b 1 
> 							d b 0 
> 							d b 0"),header=T) 
> aggregate(Number ~ Letter,data=dtf,max)
> 
> how can I adjust this solution that the results also includes "Test"?
> 
> I tried:
> 
> aggregate(Number ~ Letter,data=dtf,max,by=list("Letter", "Test", "Number"))
> 
> But it breaks with the following error message:
> 
> Error in aggregate.data.frame(mf[1L], mf[-1L], FUN = FUN, ...) : 
>   arguments must have same length
> 
> 
> 
> 
> 
> --
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> 
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-- 
Eik Vettorazzi
Institut für Medizinische Biometrie und Epidemiologie
Universitätsklinikum Hamburg-Eppendorf

Martinistr. 52
20246 Hamburg

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