[R] Error when using do.call

[Liaw, Andy]

Why not just do:

do.call("order", A[, ind])

??  A data frame is already a list.

Andy

> From: Brough, Tyler (FRS)
> 
> useRs,
> 
> I'm using version 2.0.1 on Windows XP.  I am a bit of a 
> newbie and I am
> trying to learn the concept of computing on the language.  I 
> have an example
> that I think ought to work, but will not and I am not sure 
> what I am doing
> wrong.  
> 
> I would like to sort a data frame by a list of columns.  
> Eventually I would
> like to wrap this in a function so that I could sort data 
> frames by a list
> determined from context.  Any suggestions?  Thanks for your 
> patience as I
> strive to learn some of the finer points.
> 
> Here is a reproduction of the problem:
> 
> #*************************************************************
> **************
> *************************
> A <- data.frame(X = sample(c("A","B"),size=10,replace=T), Y =
> sample(c(T,F),size = 10, replace = T),
> 	Z = sample(1:10,size=10,replace=T));
> 
> arglist <- list();
> ind <- 3:1
> for(i in 1:3) {
> 	arglist[[i]] <- as.name(paste("A[,",ind[i],"]",sep=""));
> }
> 
> do.call(what="order",args=arglist)
> #*************************************************************
> **************
> *************************
> 
> I get the following error message:
> 
> > do.call(what="order",args=arglist)
> Error in order('A[,3]','A[,2]','A[,1]') : 
> 	  Object "A[,1]" not found
> >
> 
> Thanks, 
> 
> -Tyler
> 
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