Try this:
gsub(" MIMA.*", "\\1", desc)
On Thu, May 27, 2010 at 11:37 AM, wrote:
> I have the following vector of strings (shown only the first 3 elements)
>
> > desc[1:3]
> [1] "hsa-let-7a MIMAT0000062 Homo sapiens let-7a"
> [2] "hsa-let-7a* MIMAT0004481 Homo sapiens let-7a*"
> [3] "hsa-let-7a-2* MIMAT0010195 Homo sapiens let-7a-2*"
> > is.vector(desc)
> [1] TRUE
> > A <- unlist(strsplit(desc[1:3], " "))
> > A
> [1] "hsa-let-7a MIMAT0000062 Homo sapiens let-7a"
> [2] "hsa-let-7a* MIMAT0004481 Homo sapiens let-7a*"
> [3] "hsa-let-7a-2* MIMAT0010195 Homo sapiens let-7a-2*"
> > as.vector(A)
> [1] "hsa-let-7a MIMAT0000062 Homo sapiens let-7a"
> [2] "hsa-let-7a* MIMAT0004481 Homo sapiens let-7a*"
> [3] "hsa-let-7a-2* MIMAT0010195 Homo sapiens let-7a-2*"
> >
> I would like to extract only the first field (of variable length). That is
> I need a vector containing
> "hsa-let-7a "
> "hsa-let-7a*"
> "hsa-let-7a-2*"
>
> The operator [[]][] works only on the single vector element. I would like
> to extract the 1st field
> with one single instruction rather than a loop as traditional programming
> languages request.
>
> Thank you in advance for you help.
> Maura
>
>
>
> tutti i telefonini TIM!
>
>
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>
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>
--
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O
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