[R] Regular Expression

[Rui Barradas]

Hello,

I believe the following will do it.


d <- read.table(text="
MONTH   QUARTER  YEAR
2012-07   2012-3        2012
2001-07   2001-3        2001
2002-01   2002-1        2002
", header=TRUE)

search <- "^.*-([[:digit:]]+)$"
sapply(d, function(x) as.integer(sub(search, "\\1", x)))


Hope this helps,

Rui Barradas

Em 24-07-2012 18:36, Fred G escreveu:
> Hi--
>
> I have three columns in an input file:
> MONTH   QUARTER  YEAR
> 2012-07   2012-3        2012
> 2001-07   2001-3        2001
> 2002-01   2002-1        2002
>
> I want to make output like so:
> MONTH   QUARTER  YEAR
> 07           3                2012
> 07           3                2001
> 01           1                2002
>
> I was having some trouble getting the regular expression to work.  I think
> it should be something like the following:
> tmp <- uncurated$MONTH
> *tmp <- gsub("[^-\\d\\d]","",tmp,perl=TRUE)*
> *tmp[tmp=="-"] <- ""*
> *curated$MONTH <- tmp*
> *
> *
> tmp <- uncurated$QUARTER
> *tmp <- gsub("[^-\\d]","",tmp,perl=TRUE)*
> *tmp[tmp=="-"] <- ""*
> *curated$QUARTER <- tmp*
> *
> *
> *but it's not quite working. I want to be able to isolate any digits that
> occur after the hyphen and to delete everything before and including the
> hyphen. Would greatly appreciate any clarification anyone can provide.*
>
> 	[[alternative HTML version deleted]]
>
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