[R] replace multiple values in vector at once

[David Winsemius]

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
>> 
> 
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> 
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David Winsemius
Alameda, CA, USA