* must be escaped for grep with \ and \ must be escaped for R itself
with another \, so you need
grep("\\*", c("/3", "2*3", "4-4"))
Gabor
2009/1/9 David Hajage <dhajag...@gmail.com>:
> Dear R useRs,
>
> Sorry for this foolish question, but I can't find how to escape the *
> character when using grep :
>
>> grep("-", c("/3", "2*3", "4-4"))
> [1] 3
>> grep("/", c("/3", "2*3", "4-4"))
> [1] 1
>> grep("*", c("/3", "2*3", "4-4"))
> Erreur dans grep("*", c("/3", "2*3", "4-4")) :
> expression régulière incorrecte '*'
> De plus : Warning message:
> In grep("*", c("/3", "2*3", "4-4")) :
> erreur rgcomp : 'Expression régulière précédente incorrecte'
>> grep("\*", c("/3", "2*3", "4-4"))
> Erreur dans grep("*", c("/3", "2*3", "4-4")) :
> expression régulière incorrecte '*'
> De plus : Warning messages:
> 1: '\*' est un code escape non reconnu dans une chaîne de caractères
> 2: code escape non reconnu éliminé de "\*"
> 3: In grep("*", c("/3", "2*3", "4-4")) :
> erreur rgcomp : 'Expression régulière précédente incorrecte'
>
> Best regards,
>
> david
>
> [[alternative HTML version deleted]]
>
>
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>
--
Gabor Csardi <gabor.csa...@unil.ch> UNIL DGM
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