R help - Mar 2010 - c(), or cat(), or paste(), all cause unwanted reordering

Hi,

I would expect the following:

paste(
	as.character( cat( rep( ".", 2 ) ) ),	
	"a string",
	as.character( cat( rep( ".", 3 ) ) )
);

to yield this string: ". . a string . . .", but instead it yields
this:
> . .. . .[1] " a string "
The third argument has been stuck immediately after the first.  The same
thing happens with cat() or c(). What's going on?

Thanks,
Jeff

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Hello,

Jeff Brown wrote:
> I would expect the following:
> 
> paste(
> 	as.character( cat( rep( ".", 2 ) ) ),	
> 	"a string",
> 	as.character( cat( rep( ".", 3 ) ) )
> );
> 
> to yield this string: ". . a string . . .", but instead it yields
this:
> 
>> . .. . .[1] " a string "
> 
cat is writing its output to the console, not creating an object like 
you want.  notice the second cat will return (and write to the console) 
before paste.

You need the collapse argument to paste, forget about cat for this.

Try:

pc <- function(...) paste(..., collapse = " ")
rd <- function(n) rep(".", n)
pc(pc(rd(2)), "a string", pc(rd(3)))


Probably many other ways.

--Erik

Maybe:

gsub("^(.*)$", "..\\1...", "a string")

On Thu, Mar 25, 2010 at 3:53 PM, Jeff Brown <dopethatwantscash at
yahoo.com> wrote:
>
> Hi,
>
> I would expect the following:
>
> paste(
> ? ? ? ?as.character( cat( rep( ".", 2 ) ) ),
> ? ? ? ?"a string",
> ? ? ? ?as.character( cat( rep( ".", 3 ) ) )
> );
>
> to yield this string: ". . a string . . .", but instead it yields
this:
>
>> . .. . .[1] " a string "
>
> The third argument has been stuck immediately after the first. ?The same
> thing happens with cat() or c(). What's going on?
>
> Thanks,
> Jeff
>
> --
> View this message in context:
http://n4.nabble.com/c-or-cat-or-paste-all-cause-unwanted-reordering-tp1691133p1691133.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> 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.
>


-- 
Henrique Dallazuanna
Curitiba-Paran?-Brasil
25? 25' 40" S 49? 16' 22" O

Erik Iverson wrote:
> Hello,
> 
> Jeff Brown wrote:
> 
>> I would expect the following:
>>
>> paste(
>>     as.character( cat( rep( ".", 2 ) ) ),   
>>     "a string",
>>     as.character( cat( rep( ".", 3 ) ) )
>> );
>>
>> to yield this string: ". . a string . . .", but instead it
yields this:
>>
>>> . .. . .[1] " a string "
>>
> 
> cat is writing its output to the console, not creating an object like 
> you want.  notice the second cat will return (and write to the console) 
> before paste.
> 
> You need the collapse argument to paste, forget about cat for this.
> 
> Try:
> 
> pc <- function(...) paste(..., collapse = " ")
> rd <- function(n) rep(".", n)
> pc(pc(rd(2)), "a string", pc(rd(3)))
> 
>
Or even a little bit "DRY"er:

pc <- function(...) paste(..., collapse = " ")
rd <- function(n) pc(rep(".", n))
pc(rd(2), "a string", rd(3))

cat() isn't doing what you think, and as.character()
is unnecessary here because paste() takes care of
that.

A couple of more elegant solutions have already
appeared, but here's one that parallels your version:

paste(c(
       rep( ".", 2 ),
       "a string",
       rep( ".", 3 )),
collapse=" ")



On Thu, Mar 25, 2010 at 2:53 PM, Jeff Brown <dopethatwantscash at
yahoo.com> wrote:
>
> Hi,
>
> I would expect the following:
>
> paste(
> ? ? ? ?as.character( cat( rep( ".", 2 ) ) ),
> ? ? ? ?"a string",
> ? ? ? ?as.character( cat( rep( ".", 3 ) ) )
> );
>
-- 
Sarah Goslee
http://www.functionaldiversity.org

Wow, you guys are awesome.  Thanks!
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On Thu, 2010-03-25 at 11:54 -0800, Jeff Brown wrote:
> Wow, you guys are awesome.  Thanks!

Thanks for the "cat()" question Jeff and to all guRus out there for
the
replies. This is something I was looking for the last hour.

Nikos