[R] regular expression for selection

[Petr PIKAL]

Hi

> 
> Hi,
> 
> Try grepl instead of sub,
> 
> mena[grepl("m5.", mena)]

It does not select those "m5?" strings from those character vectors. I 
need as an output a vector

m53, m54, m55, m56, m57, m58, m59

Regards
Petr


> 
> HTH,
> 
> baptiste
> 
> On 14 November 2011 21:45, Petr PIKAL <petr.pikal at precheza.cz> wrote:
> > Dear all
> >
> > I am again (as usual) lost in regular expression use for selection. 
Here
> > are my data:
> >
> >> dput(mena)
> > c("138516_10g_50ml_50c_250utes1_m53.00-_s1.imp",
> > "138516_10g_50ml_50c_250utes1_m54.00_s1.imp",
> > "138516_10g_50ml_50c_250utes1_m55.00_s1.imp",
> > "138516_10g_50ml_50c_250utes1_m56.00_s1.imp",
> > "138516_10g_50ml_50c_250utes1_m57.00_s1.imp",
> > "138516_10g_50ml_50c_250utes1_m58.00_s1.imp",
> > "138516_10g_50ml_50c_250utes1_m59.00_s1.imp")
> >
> > I want to select only values "m" foolowed by numbers from 53 to 59.
> >
> > I used
> >
> > sub("m5.", "", mena)
> >
> > which correctly selects those m53 - m59 values but, in contrary to my
> > expectation, it replaced the selected values with specified 
replacement -
> > in that case empty string.
> >
> > What I shall use if I want to get rid of all but m53-m59 from those
> > strings?
> >
> > Regards
> > Petr
> >
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> >