[R] regex - extracting 2 numbers and " from strings

[David Winsemius]

On Oct 8, 2015, at 3:45 PM, Omar André Gonzáles Díaz wrote:

> Hi I have a vector of 100 elementos like this ones:
> 
> a <- c("SMART TV LCD FHD 70\" LC70LE660", "LED FULL HD 58'' LE58D3140")
> 
> I want to put just the (70\") and (58'') in a vector b.

> sub("(^.+ )(\\d+)([\"]|[']{2})(.+$)", "\\2\\3", a)
[1] "70\"" "58''"

Also. The `stringr` package uses the code in the `stringi` package to give more compact expressions. You might want to look at 

str_extract	Extract matching patterns from a string.
str_extract_all	Extract matching patterns from a string.


> 
> This is my try, but is not working:
> 
> b <- grepl('^[0-9]{2}""$',a)
> 
> Any hint is welcome, thanks.
> 
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David Winsemius
Alameda, CA, USA