[R] paste together a string object later to be utilized in a function

[moleps islon]

I'm sorry for not clearer describing my motive with this--

So this is what I'm trying to do- Take a survival object and utilize
it in ggplot.

ggkm<-function(time,event,stratum) {


    m2s<-Surv(time,as.numeric(event))

    fit <- survfit(m2s ~ stratum)

    f$time<-fit$time

    f$surv<-fit$surv

    f$strata<-c(rep(names(fit$strata[1]),fit$strata[1]),rep(names(fit$strata[2]),fit$strata[2]))

    f$upper<-fit$upper
    f$lower<-fit$lower

    r<-ggplot (f,aes(x=time,y=surv,fill=strata,group=strata))+geom_line()+geom_ribbon(aes(ymin=lower,ymax=upper),alpha=0.3)
    return(r)
}


My problem is that I can have more than two strata, and I would like
the function to automatically detect the number of strata. Hence a
quick hack as to how I can create f$strata when I dont know the number
of strata would be appreciated.


The paste("rep(names(fit$strata[",1:length(fit$strata),"]),fit$strata[",1:length(fit$strata),"])",sep="")
is as close as I get. However this results in multiple strings and I
havent discovered yet how I can pass this so f$strata is created. This
could easily be done in stata appending to a macro, but as I am a
recent convertee I dont know how  to do this in R. (yet...?)


Regards,

//M

On Mon, Jun 7, 2010 at 2:50 AM, Joris Meys <jorismeys at gmail.com> wrote:
> Wild guess, but it looks like you are looking at :
>
>> ts <- list(a=1:5)
>> names(ts$a) <- letters[1:5]
>> v<-paste("rep(names(ts$a[",1:b,"]),ts$a[",1:b,"])",sep="")
>>
>> sapply(v,function(x){eval(parse(,text=x))})
> $`rep(names(ts$a[1]),ts$a[1])`
> [1] "a"
>
> $`rep(names(ts$a[2]),ts$a[2])`
> [1] "b" "b"
>
> $`rep(names(ts$a[3]),ts$a[3])`
> [1] "c" "c" "c"
>
> $`rep(names(ts$a[4]),ts$a[4])`
> [1] "d" "d" "d" "d"
>
> $`rep(names(ts$a[5]),ts$a[5])`
> [1] "e" "e" "e" "e" "e"
>
>> assign("test",eval(parse(text=v[3])))
>> test
> [1] "c" "c" "c"
>>
>
> Cheers
> Joris
>
> On Sun, Jun 6, 2010 at 9:51 PM, moleps <moleps2 at gmail.com> wrote:
>> Dear r-listers,
>>
>> I need to pass a string to a function. However the length of the string is dependent on the length of a vector.
>>
>>
>> b<-length(h)
>> v<-paste("rep(names(ts$a[",1:b,"]),ts$a[",1:b,"])",sep="")
>>
>>
>> Is it possible somehow to pass this as an argument to a function later on ?
>>
>>
>>
>> Regards,
>>
>> //M
>>
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>
>
>
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> Ghent University
> Faculty of Bioscience Engineering
> Department of Applied mathematics, biometrics and process control
>
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