R help - Jul 2003 - how to divide a string into characters? - for comparing strings that is

Hi

I am searching for a way to do something like "ABC" ->
c("A","B","C"). How can this be accomplished?

I tried cut() and split(), but they do something else, it seems.

The purpose for doing this is to find the number of common (and uncommon)
characters, i.e. ultimately I want something like this:
> foo("ABD","ADE")
c(2,1) # 2 in x are in y, 1 in y is not in x
> foo("AB","ADE")
c(1,2) # 1 in x is in y, 2 in y are not in x

Maybe I even do not need the string splitting?

I hope I was clear in stating my problem.

Thank you for your valuable input,
David

David Andel wrote:
>Hi
>
>I am searching for a way to do something like "ABC" ->
c("A","B","C"). How can this be accomplished?
>  
>
Try

strsplit("ABC", "")[[1]]
>I tried cut() and split(), but they do something else, it seems.
>
>The purpose for doing this is to find the number of common (and uncommon)
characters, i.e. ultimately I want something like this:
>
>  
>
>>foo("ABD","ADE")
>>    
>>
>c(2,1) # 2 in x are in y, 1 in y is not in x
>  
>
>>foo("AB","ADE")
>>    
>>
>c(1,2) # 1 in x is in y, 2 in y are not in x
>
>Maybe I even do not need the string splitting?
>
>I hope I was clear in stating my problem.
>
>Thank you for your valuable input,
>David
>
>______________________________________________
>R-help at stat.math.ethz.ch mailing list
>https://www.stat.math.ethz.ch/mailman/listinfo/r-help
>
>
>  
>

Here is a way of doing by splitting the character strings.

x <- "ABD"
y <- "ADE"
x <- unlist(strsplit(x,""))
y <- unlist(strsplit(y,""))
c(sum(as.logical(match(x,y,nomatch=0))),
sum(!as.logical(match(y,x,nomatch=0))))

HTH,
Jerome

On July 17, 2003 03:07 pm, David Andel wrote:
> Hi
>
> I am searching for a way to do something like "ABC" ->
c("A","B","C").
> How can this be accomplished?
>
> I tried cut() and split(), but they do something else, it seems.
>
> The purpose for doing this is to find the number of common (and 
uncommon) characters, i.e. ultimately I want something like
this:
> > foo("ABD","ADE")
>
> c(2,1) # 2 in x are in y, 1 in y is not in x
>
> > foo("AB","ADE")
>
> c(1,2) # 1 in x is in y, 2 in y are not in x
>
> Maybe I even do not need the string splitting?
>
> I hope I was clear in stating my problem.
>
> Thank you for your valuable input,
> David
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help

Dear David

At 12:07 AM 7/18/2003 +0200, David Andel wrote:
>I am searching for a way to do something like "ABC" ->
c("A","B","C"). How
>can this be accomplished?
>
>I tried cut() and split(), but they do something else, it seems.
>
>The purpose for doing this is to find the number of common (and uncommon) 
>characters, i.e. ultimately I want something like this:
>
> > foo("ABD","ADE")
>c(2,1) # 2 in x are in y, 1 in y is not in x
> > foo("AB","ADE")
>c(1,2) # 1 in x is in y, 2 in y are not in x
>
>Maybe I even do not need the string splitting?
>
>I hope I was clear in stating my problem.
Here's a solution based on splitting the strings:

 > foo <- function(a, b){
+     a <- strsplit(a, "")[[1]]
+     b <- strsplit(b, "")[[1]]
+     nmatch <- sum(outer(a, b, "=="))
+     c(nmatch, length(b) - nmatch)
+     }
 > foo("ABD","ADE")
[1] 2 1
 > foo("AB","ADE")
[1] 1 2

By the way, apropos() turns up strsplit():

 > apropos("split")
  [1] "split"              "split.data.frame"  
"split.data.frame<-"
  [4] "split.default"      "split.screen"      
"split<-"
  [7] "split<-.data.frame" "split<-.default"   
"strsplit"
[10] "unsplit"

I hope that this helps,
  John

-----------------------------------------------------
John Fox
Department of Sociology
McMaster University
Hamilton, Ontario, Canada L8S 4M4
email: jfox at mcmaster.ca
phone: 905-525-9140x23604
web: www.socsci.mcmaster.ca/jfox