replace multiple values in vector at once

On Jul 12, 2013, at 2:56 PM, Trevor Davies wrote:

I always think that replying to your own r-help feels silly but it's good
to close these things out.

here's my hack solution:

x1<-merge(data.frame(A=x),data.frame(A=c('x','y','z'),B=c(1,2,2)),by='A')[,2]

That fairly tortured compared with:

x <- c(rep('x',3),rep('y',3),rep('z',3))

x1b <- as.character(1:3)[ match(x, c("x","y","z") ) ]
x1b

Furthermore, your solution does not deliver the answer you expected.

--
David.

Well that works and should for my more complex situation.  If anyone has
something a little less heavy handed I'd live to hear it.

Have a great weekend.


On Fri, Jul 12, 2013 at 2:18 PM, Trevor Davies <davies.trevor at gmail.com>wrote:

I'm trying to find a function that can replace multiple instances of
values or characters in a vector in a one step operation.  As an example,
the vector:

x <- c(rep('x',3),rep('y',3),rep('z',3))

x

[1] "x" "x" "x" "y" "y" "y" "z" "z" "z"

I would simply like to replace all of the x's with 1's, y:2 & z:3 (or
other characters).
i.e:

x

[1] "1" "1" "1" "2" "2" "2" "3" "3" "3"

Of course, I'm aware of the replace function but this obviously gets a
little unwieldy when there are :
x<-replace(x,x=='x',1)
x<-replace(x,y=='x',2)
x<-replace(x,z=='x',3)

but I can't figure out how to do it in a one stop operation.  My real
needs is more complex obviously.  This is one of those seemingly simple
r-operations that should be obvious but I'm coming up empty on this one.

Thanks for the help.
Trevor

      [[alternative HTML version deleted]]

David Winsemius
Alameda, CA, USA