This should do it, assuming you data is in a data frame called dat:
sel <- unique(dat$V1)
ix <- match(sel,dat$V1)
dat[ix,]
On 09/02/07, Glazko, Galina <Galina_Glazko at urmc.rochester.edu>
wrote:> Dear list,
>
>
>
> I have a table where first 3 columns are identical if the name in the
> first column is the same, and
>
> the number in N4 is slightly different for all identical names, like
> this:
>
> -------------------------------------------------------------------
>
> 29 Mm.1_at 3 + 93649936
>
> 30 Mm.1_at 3 + 93649990
>
> 31 Mm.1_at 3 + 93649993
>
> 32 Mm.1_at 3 + 93650001
>
> 33 Mm.1_at 3 + 93650010
>
> 34 Mm.10_at 4 + 147438101
>
> 35 Mm.10_at 4 + 147438192
>
> 36 Mm.10_at 4 + 147438214
>
> 37 Mm.100043_at 5 + 31602952
>
> 38 Mm.100043_at 5 + 31602982
>
> 39 Mm.100043_at 5 + 31603000
>
> -------------------------------------------------------------------
>
>
>
> I need to select unique identifiers in column N 1, without paying
> attention to what is in column N4, taking the first number in N4
> corresponding to first unique ID in N1, like this:
>
> 29 Mm.1_at 3 + 93649936
>
> 34 Mm.10_at 4 + 147438101
>
> 37 Mm.100043_at 5 + 31602952
>
>
>
> Could someone tell me how to do it without FOR cycle over all IDs in N1?
>
>
>
> Thank you!
>
>
>
> Best regards
>
> Galina
>
>
>
>
>
>
> [[alternative HTML version deleted]]
>
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--
================================David Barron
Said Business School
University of Oxford
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