[R] add vectors to multiple objects

[David Winsemius]

On Aug 3, 2012, at 8:19 AM, John linux-user wrote:

> Hi David,
>
> Thanks for response, but my key question still remains unsolved.  
> That is, how to add many vectors (L1,L2,L3....) to many list objects  
> (a.list, b.list....) in a workspace?
>
> listObjects=ls(pattern=".list") #for example,  a.list, b.list...
>
>
> for (object in listObjects){
>
> #how to sign vectors L1,L2,..Ln to each object (a.list, b.list...)
>
>
> }
>
> Any suggestions/comments/ideas will be appreciated.

Can we have code that creates these entities in the workspace? (That  
is what is meant as a reproducible example.)  I cannot tell whether  
there are already objects named "L1", "L2",... to which you wish to  
append the value of the objects found,  or  that you want to assign  
values to names that only exist as character vectors.

-- 
David.

>
> John
>
>
> From: David Winsemius <dwinsemius at comcast.net>
> To: John linux-user <johnlinuxuser at yahoo.com>
> Cc: "r-help at r-project.org" <r-help at r-project.org>
> Sent: Wednesday, August 1, 2012 7:21 PM
> Subject: Re: [R] add vectors to multiple objects
>
>
> On Aug 1, 2012, at 8:11 AM, John linux-user wrote:
>
> > Hi everyone,
> >
> > I try to add many vectors (L1,L2,L3....) to many list objects  
> (a.list, b.list....) in a workspace. Somethings like below, but it  
> is not working. Any suggestions will be appreciated. Best, John
> >
> > lf=ls(pattern=".lst")
> >
> >  for (x in listfiles) {
> >    dat=read.delim(x,header=F)
>
> Presumably that would fail since 'listfiles' has not been defined.  
> did you mean 'lf'? If you did,then wouldn't the second line  
> overwrite all the early values of "dat" leaving only the last one?
>
> Perhaps:
>   datfils <- list()
>   for (x in listfiles) {
>     datfils[x] <- read.delim(x,header=F)
>
>
> >
> >    for (i in 1: lf) {
>
> And that would fail because 'lf' is a character vector, and it's not  
> meaningful to specify such a range. Try instead:
>
>     for (i in names(datfils[x]) ) {
> #
> # which will then iterate over the names of the files which are now  
> also the names of the list elements
>
> >    assign(i$add,as.numeric(dat[,3]))
>
> But since 'i' is a length-1 character vector, the expression `i$add`  
> will be meaningless. The "$" operator does not do function calling  
> in R unless you do fancy things with environments, and you cannot  
> "sub-assign" in that manner, at least not with the assign() function.
>
> Try instead:
>
>     assign(i, as.numeric(datfils[x][,3]))
>     names(i)[length(i)] <- "add"
>
> Or:
>     i <- transform(i, add=datfils[x][,3] )
>
>
>
> >  #or i$add=as.numeric(dat[,3]
> >    names(i)[names(i)=="add"]=substr(x,1,5)
>
> I'm not sure these would be doing the same thing. What was your goal  
> here?
>
> >
> >    print (i[1:3,])
> >  }
> > }
>
>
> David Winsemius, MD
> Alameda, CA, USA
>
>
>

David Winsemius, MD
Alameda, CA, USA