Jim/Stephan - absolutely perfect.   thank you.

very grateful for your help.

simeon

On Sat, Mar 28, 2009 at 5:27 PM, jim holtman <jholtman@gmail.com> wrote:

> Does this do what you want:
>
> > x <- c('xxxredxxx', 'xxxxbluexxxx', 'xxxxxx', 'greenbluered')
> > pat <- 'red|green|blue'
> > result <- sub(paste("^.*?(", pat, ").*", sep=""), "\\1", x)
> > # check if no match in original string; replace with 'other'
> > match <- grep(pat, x)
> > result[-match] <- 'other'
> > result
> [1] "red"   "blue"  "other" "red"
> >
> >
>
>
> On Sat, Mar 28, 2009 at 1:08 PM, Stephan Kolassa <Stephan.Kolassa@gmx.de>
> wrote:
> > Hi Simeon,
> >
> > I played around a little with Vectorize and mapply, but I couldn't make
> it
> > work :-( So, my best guess would be a simple loop like this:
> >
> > result <- as.character(paste(letters,colours(),"stuff",LETTERS))
> > target <- c("red","blue","green","gray")
> > for ( new.color in target ) { result[grep(new.color,result)] <- new.color
> }
> >
> > Best of luck,
> > Stephan
> >
> >
> > simeon duckworth schrieb:
> >>
> >> stephan
> >>
> >> sorry for not being clear - but thats exactly what i want.
> >>
> >> i'd like to replace every complex string that contains "red" with just
> >> "red", and then so on with "blue", "yellow" etc
> >>
> >> my data is of the form
> >>
> >> "xxxxx xx xx xxxxx  red xx xxx xx"
> >> "xx xxx xxx xx  blue xx xx xx xx x"
> >> "x xx xxxxxxxx xx xx xx xxxx red"
> >> "red xx xx xx xx xx"
> >> "xx xx xx xx xx xx"
> >> "xx x x x x xxxx"
> >>
> >> which i'd like to replace with
> >> "red"
> >> "blue"
> >> "red"
> >> "other"
> >> "other"
> >>
> >> thanks
> >>
> >>
> >> On Sat, Mar 28, 2009 at 2:38 PM, Stephan Kolassa
> >> <Stephan.Kolassa@gmx.de>wrote:
> >>
> >>> Hi Simeon,
> >>>
> >>> I'm slightly unclear on what exactly you are trying to achieve... Are
> you
> >>> trying to replace every entry of colours which *contains* "red" by
> "red",
> >>> dropping the rest of the entry? And same with "blue"?
> >>>
> >>> A short example "before & after" would be helpful...
> >>>
> >>> Best,
> >>> Stephan
> >>>
> >>>
> >>> simeon duckworth schrieb:
> >>>
> >>>  thanks stephan.  i'd been trying to make gsub work, but couldnt make
> it
> >>>>
> >>>> replace the whole expression.  so i'd resorted to trying to loop with
> >>>> grep
> >>>> -
> >>>> but with two problems.   firstly, i cant seem to make the loop
> >>>> 'remember'
> >>>> the substitutions it makes (see below).  secondly, it feels like this
> is
> >>>> a
> >>>> really inefficient way of doing something quite simple anyhow.
> >>>>
> >>>> colours <- as.character(paste(letters,colours(),"stuff",LETTERS))
> >>>> target <- c("red","blue","green","gray")
> >>>> new.colour <-colours
> >>>> for (i in length(target)) {
> >>>>   x <- target[i]
> >>>>   new.colour[grep((x),new.colour)] <- x
> >>>>   return(new.colour)
> >>>>   }
> >>>>
> >>>>
> >>>>
> >>>>
> >>>> On Sat, Mar 28, 2009 at 9:45 AM, Stephan Kolassa <
> Stephan.Kolassa@gmx.de
> >>>>>
> >>>>> wrote:
> >>>>
> >>>>  Hi Simeon,
> >>>>>
> >>>>> ?gsub
> >>>>>
> >>>>> HTH,
> >>>>> Stephan
> >>>>>
> >>>>> simeon duckworth schrieb:
> >>>>>
> >>>>>  I am trying to simplify a text variable by matching and replacing it
> >>>>>>
> >>>>>> with
> >>>>>> a
> >>>>>> string in another vector
> >>>>>>
> >>>>>> so for example in
> >>>>>> colours <- paste(letters,colours(),"stuff",LETTERS)
> >>>>>>
> >>>>>> find and replace with ("red","blue","green","gray","yellow","other")
> >>>>>>  -
> >>>>>> irrespective of case
> >>>>>>
> >>>>>> its a large dataset, so i'd like to be able to do this as
> efficiently
> >>>>>> as
> >>>>>> possible.
> >>>>>>
> >>>>>> thanks for any help
> >>>>>>
> >>>>>>      [[alternative HTML version deleted]]
> >>>>>>
> >>>>>> ______________________________________________
> >>>>>> R-help@r-project.org mailing list
> >>>>>> https://stat.ethz.ch/mailman/listinfo/r-help
> >>>>>> PLEASE do read the posting guide
> >>>>>> http://www.R-project.org/posting-guide.html
> >>>>>> and provide commented, minimal, self-contained, reproducible code.
> >>>>>>
> >>>>>>
> >>>>>>
> >>
> >
> > ______________________________________________
> > R-help@r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
>
>
>
> --
> Jim Holtman
> Cincinnati, OH
> +1 513 646 9390
>
> What is the problem that you are trying to solve?
>

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