R help - Sep 2011 - how to quote "factors" in a function?

### code ###
    x=sample(LETTERS[1:26],100,T)
    prob=function(y){
            count=sum(x==y)
            total=length(x)
            count/total
    }
### end ###

How do I quote the letters A,B,C,D ect, in order to make the "prob"
function
return the weights of the desired Letter?

Thanks!

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You quote them in quotes. "A"

Also: bad scoping. 

Michael Weylandt

On Sep 11, 2011, at 6:11 PM, casperyc <casperyc at hotmail.co.uk> wrote:
> ### code ###
>    x=sample(LETTERS[1:26],100,T)
>    prob=function(y){
>            count=sum(x==y)
>            total=length(x)
>            count/total
>    }
> ### end ###
> 
> How do I quote the letters A,B,C,D ect, in order to make the
"prob" function
> return the weights of the desired Letter?
> 
> Thanks!
> 
> --
> View this message in context:
http://r.789695.n4.nabble.com/how-to-quote-factors-in-a-function-tp3805913p3805913.html
> Sent from the R help mailing list archive at Nabble.com.
> 
> ______________________________________________
> R-help at 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.

Hi casperyc,

Try

# option 1
x <- sample(LETTERS[1:26], 100, TRUE)

prob <- function(y){
           count=sum(x==y)
           total=length(x)
           count/total
         }
prob('A')
prob('B')
prob('Z')


# option 2
tx <- prop.table(table(x))
tx
tx['A']

# option 2.1
foo <- function(x, l = NULL){
    tx <- prop.table(table(x))
    if(is.null(l)){
      r <- tx
        }
       else r <- tx[l]
      r
    }

foo(x)
foo(x, 'A')

HTH,
Jorge


On Sun, Sep 11, 2011 at 6:11 PM, casperyc <> wrote:
> ### code ###
>    x=sample(LETTERS[1:26],100,T)
>    prob=function(y){
>            count=sum(x==y)
>            total=length(x)
>            count/total
>    }
> ### end ###
>
> How do I quote the letters A,B,C,D ect, in order to make the
"prob"
> function
> return the weights of the desired Letter?
>
> Thanks!
>
> --
> View this message in context:
>
http://r.789695.n4.nabble.com/how-to-quote-factors-in-a-function-tp3805913p3805913.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> 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.
>
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