[R] Better use of regex

[ruipbarradas at sapo.pt]

Hello,

What about the following?

ff <- dimInfo[grep('HS', dimInfo)]
sub("^.*HS_([[:alnum:]]).*$", "\\1", ff)


Hope this helps,

Rui Barradas


Citando Doran, Harold <HDoran at air.org>:

> I have produced a terribly inefficient piece of codes. In the end,  
> it gives exactly what I need, but clumsily steps through multiple  
> steps which I'm sure could be more efficiently reduced.
>
> Below is a reproducible example. What I have to begin with is  
> character vector, dimInfo. What I want to do is parse this vector 1)  
> find the elements containing 'HS' and 2) grab *only* the first  
> character after the "HS_". The final line of code in the example  
> gives what I need.
>
> Any suggestions on a better approach?
>
> Harold
>
>
> dimInfo <- c("RecordID", "oppID", "position", "key", "operational",  
> "IsSelected",
> "score", "item_1_HS_conv_ovrl_scr", "item_1_HS_elab_ovrl_scr",
> "item_1_HS_org_ovrl_scr")
>
> ff <- dimInfo[grep('HS', dimInfo)]
> gg <- strsplit(ff, 'HS_')
> hh <- sapply(1:3, function(i) gg[[i]][2])
> substr(hh, 1, 1)
>
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