R help - Oct 2008 - A question about "union"

Dear all,

    I have a question about "union".  "union" handles two
vectors'
elements to get their union, but I have many vectors and I want to get 
the union of all of them. So I wrote a loop:

all <-c();
for(var in ls(pattern="xyz"))
# all of the vectors with pattern of "xyz"
{
    all <- union(all, var);
}


but the result is like this: ("xyzblabla1", "xyzblabla2",
"abcxyz", ...
) -- just a collection of the variable names, not the union of their 
elements.

How can I solve this problem?

thanks!

Leon

You need to get() their elements instead of merely using variable names.

Regards,
Yihui
--
Yihui Xie <xieyihui at gmail.com>
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Renmin University of China, Beijing, 100872, China



On Fri, Oct 17, 2008 at 6:23 PM, Leon Yee <yee.leon at gmail.com>
wrote:
> Dear all,
>
>   I have a question about "union".  "union" handles two
vectors' elements to
> get their union, but I have many vectors and I want to get the union of all
> of them. So I wrote a loop:
>
> all <-c();
> for(var in ls(pattern="xyz"))
> # all of the vectors with pattern of "xyz"
> {
>   all <- union(all, var);
> }
>
>
> but the result is like this: ("xyzblabla1",
"xyzblabla2", "abcxyz", ... ) --
> just a collection of the variable names, not the union of their elements.
>
> How can I solve this problem?
>
> thanks!
>
> Leon
>
> ______________________________________________
> 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.
>

Leon Yee wrote:
> Dear all,
>
>    I have a question about "union".  "union" handles
two vectors'
> elements to get their union, but I have many vectors and I want to get
> the union of all of them. So I wrote a loop:
>
> all <-c();
> for(var in ls(pattern="xyz"))
> # all of the vectors with pattern of "xyz"
> {
>    all <- union(all, var);
> }
>
>
> but the result is like this: ("xyzblabla1",
"xyzblabla2", "abcxyz",
> ... ) -- just a collection of the variable names, not the union of
> their elements.
>
> How can I solve this problem?
>
This has nothing to do with union()  and everything to do with get(). So
read the help page of the latter.

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