R help - Feb 2018 - using cat to log to file with sapply

Hi List,
I am trying to write unsuccessfully to a logfile with cat. Here my example code:

letters[1:5]->x
logf<-"test.txt"
cat('%%%%%%%%%%%%%%%%%%%%%%%%%%\n',file=logf)
catf<-function(x,...,logfile='log.txt', append=TRUE){
cat(x,'\n', file=logfile, append=append)}
testit<-function(x,...){
  paste0('this is x: ',x)->y
  return(y)
  catf("++++++++++++++++++test=============",...)
  }  
sapply(x, function(x) testit(x, logfile=logf))

Any suggestions appreciated.

Thanks
Herry

testit<-function(x,...){
  paste0('this is x: ',x)->y
  return(y)
  catf("++++++++++++++++++test=============",...)
  }

You return from the function before calling catf().  Remove the
'return(y)'
and make 'y' the last expression in the function.

Bill Dunlap
TIBCO Software
wdunlap tibco.com

On Wed, Feb 14, 2018 at 4:16 PM, <Alexander.Herr at csiro.au> wrote:
> Hi List,
> I am trying to write unsuccessfully to a logfile with cat. Here my example
> code:
>
> letters[1:5]->x
> logf<-"test.txt"
> cat('%%%%%%%%%%%%%%%%%%%%%%%%%%\n',file=logf)
> catf<-function(x,...,logfile='log.txt', append=TRUE){
cat(x,'\n',
> file=logfile, append=append)}
> testit<-function(x,...){
>   paste0('this is x: ',x)->y
>   return(y)
>   catf("++++++++++++++++++test=============",...)
>   }
> sapply(x, function(x) testit(x, logfile=logf))
>
> Any suggestions appreciated.
>
> Thanks
> Herry
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>
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Your call to catf in testit is after the return,  so it is never called. 

FWIW my antibugging strategy (and readability strategy) is to never use the
return function... I structure my logic to end up at the end with my desired
function result in a variable and I simply put that variable on the last line of
the function.
-- 
Sent from my phone. Please excuse my brevity.

On February 14, 2018 4:16:19 PM PST, Alexander.Herr at csiro.au
wrote:
>Hi List,
>I am trying to write unsuccessfully to a logfile with cat. Here my
>example code:
>
>letters[1:5]->x
>logf<-"test.txt"
>cat('%%%%%%%%%%%%%%%%%%%%%%%%%%\n',file=logf)
>catf<-function(x,...,logfile='log.txt', append=TRUE){
cat(x,'\n',
>file=logfile, append=append)}
>testit<-function(x,...){
>  paste0('this is x: ',x)->y
>  return(y)
>  catf("++++++++++++++++++test=============",...)
>  }  
>sapply(x, function(x) testit(x, logfile=logf))
>
>Any suggestions appreciated.
>
>Thanks
>Herry
>______________________________________________
>R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>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.

Not sure what you wanted to do.Note that you have  "test'txt" and
"log.txt"
in your code. Using only "test.txt", the following worked fine for me:

letters[1:5]->x
logf<-"test.txt"
cat('%%%%%%%%%%%%%%%%%%%%%%%%%%\n',file=logf)
catf<-function(x,...,logfile='test.txt', append=TRUE){
cat(x,'\n',
file=logfile, append=append)}
testit<-function(x,...){
   paste0('this is x: ',x)->y
   catf(y)
}
sapply(x, function(x) testit(x, logfile=logf))

If you do not see the file in your working directory (found by getwd() ),
maybe you have write permissions issues.

Note also that you may need none of this: see ?sink

Cheers,
Bert



Bert Gunter

"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )

On Wed, Feb 14, 2018 at 4:16 PM, <Alexander.Herr at csiro.au> wrote:
> Hi List,
> I am trying to write unsuccessfully to a logfile with cat. Here my example
> code:
>
> letters[1:5]->x
> logf<-"test.txt"
> cat('%%%%%%%%%%%%%%%%%%%%%%%%%%\n',file=logf)
> catf<-function(x,...,logfile='log.txt', append=TRUE){
cat(x,'\n',
> file=logfile, append=append)}
> testit<-function(x,...){
>   paste0('this is x: ',x)->y
>   return(y)
>   catf("++++++++++++++++++test=============",...)
>   }
> sapply(x, function(x) testit(x, logfile=logf))
>
> Any suggestions appreciated.
>
> Thanks
> Herry
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>
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