R help - Apr 2011 - converting "call" objects into character

Dear all,



I would like to log the calls to my functions. I am trying to do this using the
function match.call():



fTest<-function(x)

{

      theCall<-match.call()

      print(theCall)

      return(x)

}


> fTest(2)
fTest(x = 2)

[1] 2



I can see "theCall" printed into the console, but I don't manage
to convert it into a character to write it into a log file with other
informations.

Can anyone help?



Many thanks,



Samuel


	[[alternative HTML version deleted]]

On Apr 3, 2011, at 12:14 PM, Samuel Le wrote:
> Dear all,
>
>
>
> I would like to log the calls to my functions. I am trying to do  
> this using the function match.call():
fTest<-function(x)

{  theCall<-match.call()
       print(theCall)
       return(list(x=x, logf = theCall))
}
>
 > fTest(x=2)$x
[1] 2
 > fTest(x=2)$logf
fTest(x = 2)
 > str(fTest(x=2)$logf)
  language fTest(x = 2)

You may want to convert that  call component to a character object,  
since:

 > cat(fTest(x=2)$logf)
Error in cat(list(...), file, sep, fill, labels, append) :
   argument 1 (type 'language') cannot be handled by 'cat'
>
> I can see "theCall" printed into the console, but I don't
manage to
> convert it into a character to write it into a log file with other  
> informations.
>
> Can anyone help?


David Winsemius, MD
West Hartford, CT

On Sun, Apr 3, 2011 at 12:14 PM, Samuel Le <Samuel.Le at srlglobal.com>
wrote:
> Dear all,
>
>
>
> I would like to log the calls to my functions. I am trying to do this using
the function match.call():
>
>
>
> fTest<-function(x)
>
> {
>
> ? ? ?theCall<-match.call()
>
> ? ? ?print(theCall)
>
> ? ? ?return(x)
>
> }
>
>
>
>> fTest(2)
>
> fTest(x = 2)
>
> [1] 2
>
>
>
> I can see "theCall" printed into the console, but I don't
manage to convert it into a character to write it into a log file with other
informations.
>
See ?trace

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