[R] How to delete duplicate cases?

[Patrizio Frederic]

this works

cno 	= c(rep(1342,times=3),rep(2568,times=2))
rank	= c(.23,.14,.56,.15,.89)

df1	= data.frame(cno,rank)[order(cno,rank),]

cnou	= unique(cno)
ind	= match(cno,cnou)
where	= tapply(rank,ind,length)
where	= cumsum(as.numeric(where))

df1[where,]


regards,

PF


2008/7/24 Daniel Wagner <danieljm1976 at yahoo.com>:
> Dear R users,
>
> I have a dataframe with lot of duplicate cases and I want to delete duplicate ones which have low rank and keep that case which has highest rank.
> e.g
>
>> df1
>   cno      rank
> 1  1342    0.23
> 2  1342    0.14
> 3  1342    0.56
> 4  2568    0.15
> 5  2568    0.89
>
> so I want to keep 3rd and 5th  cases with highest rank (0.56 & 0.89) and delete rest of the duplicate cases.
> Could somebody help me?
>
> Regards
>
> Daniel
> Amsterdam
>
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