R help - Jun 2010 - paste together a string object later to be utilized in a function

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

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
>
> ______________________________________________
> 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.
>


-- 
Ghent University
Faculty of Bioscience Engineering
Department of Applied mathematics, biometrics and process control

tel : +32 9 264 59 87
Joris.Meys at Ugent.be
-------------------------------
Disclaimer : http://helpdesk.ugent.be/e-maildisclaimer.php

Does the collapse argument to the paste function do what you want?  Possibly
nested inside another paste.

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
801.408.8111

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of moleps
> Sent: Sunday, June 06, 2010 1:51 PM
> To: r-help at r-project.org
> Subject: [R] paste together a string object later to be utilized in a
> function
> 
> 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
> 
> ______________________________________________
> 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.

Sorry for bothering all of you. In the end it turned out to be much simpler than
I thought. Takes a while to get used to the vectorizing idea.



require(survival)
require(ggplot2)

ggkm<-function(time,event,stratum) {
	
	stratum<-as.factor(stratum)
	m2s<-Surv(time,as.numeric(event))
	
	fit <- survfit(m2s ~ stratum)
	
	w<-fit$time
	
	k<-fit$surv
	o<-length(levels(stratum))
	strata<-c(rep(names(fit$strata[1:o]),fit$strata[1:o]))

	upper<-fit$upper
	lower<-fit$lower
	f<-data.frame(w,k,strata,upper,lower)
	
	r<-ggplot
(f,aes(x=w,y=k,fill=strata,group=strata))+geom_line(aes(color=strata))+geom_ribbon(aes(ymin=lower,ymax=upper),alpha=0.3)+xlim(0,fit$maxtime)+ylim(0,1)
	r<-r+scale_fill_brewer(f$strata,palette="Set1")+scale_color_brewer(f$strata,palette="Set1")
	return(r)
}





data(lung)
with(lung,ggkm(time,status,sex))

with(lung,ggkm(time,status,pat.karno))





//M





On 7. juni 2010, at 22.31, Greg Snow wrote:
> Does the collapse argument to the paste function do what you want? 
Possibly nested inside another paste.
> 
> -- 
> Gregory (Greg) L. Snow Ph.D.
> Statistical Data Center
> Intermountain Healthcare
> greg.snow at imail.org
> 801.408.8111
> 
> 
>> -----Original Message-----
>> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
>> project.org] On Behalf Of moleps
>> Sent: Sunday, June 06, 2010 1:51 PM
>> To: r-help at r-project.org
>> Subject: [R] paste together a string object later to be utilized in a
>> function
>> 
>> 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
>> 
>> ______________________________________________
>> 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.