R help - Feb 2012 - ifelse

Hello,

I need to print a screen message after a test.
>list<-c("10","1","100","10")
>ifelse(all(list %in%
c(1,10,100)==TRUE),cat("YES\n"),cat("NO\n"))
YES
Error in ifelse(all(l %in% c(1, 10, 100) == TRUE), cat("YES\n"),
cat("NO\n")) :
  replacement has length zero


I have the correct answer, YES, but with an Error.

Why?

TY for any help


Arnaud Gaboury
?
A2CT2 Ltd.

cat() returns a null value so it's problematic inside ifelse. Here you
probably need a regular if statement:

if(all(list %in% c(1, 10, 100))) cat("YES\n") else
cat("NO\n") # The
== TRUE is redundant.

Michael

On Thu, Feb 9, 2012 at 11:37 AM, Arnaud Gaboury
<arnaud.gaboury at a2ct2.com> wrote:
> Hello,
>
> I need to print a screen message after a test.
>
>>list<-c("10","1","100","10")
>>ifelse(all(list %in%
c(1,10,100)==TRUE),cat("YES\n"),cat("NO\n"))
> YES
> Error in ifelse(all(l %in% c(1, 10, 100) == TRUE), cat("YES\n"),
cat("NO\n")) :
> ?replacement has length zero
>
>
> I have the correct answer, YES, but with an Error.
>
> Why?
>
> TY for any help
>
>
> Arnaud Gaboury
>
> A2CT2 Ltd.
>
> ______________________________________________
> 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.

On Feb 9, 2012, at 11:37 AM, Arnaud Gaboury wrote:
> Hello,
>
> I need to print a screen message after a test.
>
>> list<-c("10","1","100","10")
>> ifelse(all(list %in%
c(1,10,100)==TRUE),cat("YES\n"),cat("NO\n"))
> YES
> Error in ifelse(all(l %in% c(1, 10, 100) == TRUE), cat("YES\n"),
> cat("NO\n")) :
>  replacement has length zero
>
>
> I have the correct answer, YES, but with an Error.
>
> Why?
cat() returns NULL. Why ar enou not just returning the strings  
themselves or if you want to see the results as well as assign, then  
use print() which does return its arguments.

>
> TY for any help
>
>
> Arnaud Gaboury
>
> A2CT2 Ltd.
>
> ______________________________________________
> 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.
David Winsemius, MD
West Hartford, CT