Re: [R] if-else that returns vector
This is very interesting. Thanks for sharing.
On Fri, Oct 13, 2023 at 10:25 AM Richard O'Keefe wrote:
>
> ?ifelse
> 'ifelse' returns a value with the same shape as 'test' which is
> filled with elements selected from either 'yes' or 'no' depending
> on whether the element of 'test' is 'TRUE' or 'FALSE'.
>
> This is actually rather startling, because elsewhere in the
> S (R) language, operands are normally replicated to the length
> of the longer. Thus
> c(1,2,3)*10 + c(5,6)
> first (notionally) replicates 10 to c(10,10,10)
> and then c(5,6) to c(5,6,5), yielding c(15,26,35).
> And this *does* happen, sort of.
> > ifelse(c(F,T,F), c(1,2,3), c(5,6))
> => 5 2 5.
> But it *doesn't* apply to the test.
>
> There's another surprise. Years ago I expected that
> all three arguments would be evaluated, then length
> adjusted, and then processing would be done.
> But the 2nd argument is evaluated (in full) if and only
> if some element of the test is true,
> and the 3rd argument is evaluated (in full) if and oly
> if some element of the test is false.
> ifelse(c(NA,NA), stop("true"), stop("false"))
> => c(NA,NA).
>
> At any rate, what you want is if () else
>
>
>
> On Fri, 13 Oct 2023 at 09:22, Christofer Bogaso
> wrote:
>>
>> Hi,
>>
>> Following expression returns only the first element
>>
>> ifelse(T, c(1,2,3), c(5,6))
>>
>> However I am looking for some one-liner expression like above which
>> will return the entire vector.
>>
>> Is there any way to achieve this?
>>
>> __
>> R-help@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.
__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] if-else that returns vector
?ifelse
'ifelse' returns a value with the same shape as 'test' which is
filled with elements selected from either 'yes' or 'no' depending
on whether the element of 'test' is 'TRUE' or 'FALSE'.
This is actually rather startling, because elsewhere in the
S (R) language, operands are normally replicated to the length
of the longer. Thus
c(1,2,3)*10 + c(5,6)
first (notionally) replicates 10 to c(10,10,10)
and then c(5,6) to c(5,6,5), yielding c(15,26,35).
And this *does* happen, sort of.
> ifelse(c(F,T,F), c(1,2,3), c(5,6))
=> 5 2 5.
But it *doesn't* apply to the test.
There's another surprise. Years ago I expected that
all three arguments would be evaluated, then length
adjusted, and then processing would be done.
But the 2nd argument is evaluated (in full) if and only
if some element of the test is true,
and the 3rd argument is evaluated (in full) if and oly
if some element of the test is false.
ifelse(c(NA,NA), stop("true"), stop("false"))
=> c(NA,NA).
At any rate, what you want is if () else
On Fri, 13 Oct 2023 at 09:22, Christofer Bogaso
wrote:
> Hi,
>
> Following expression returns only the first element
>
> ifelse(T, c(1,2,3), c(5,6))
>
> However I am looking for some one-liner expression like above which
> will return the entire vector.
>
> Is there any way to achieve this?
>
> __
> R-help@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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__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] if-else that returns vector
Às 21:22 de 12/10/2023, Christofer Bogaso escreveu: Hi, Following expression returns only the first element ifelse(T, c(1,2,3), c(5,6)) However I am looking for some one-liner expression like above which will return the entire vector. Is there any way to achieve this? __ R-help@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. Hello, I don't like it but ifelse(rep(T, length(c(1,2,3))), c(1,2,3), c(5,6)) maybe you should use max(length(c(1, 2, 3)), length(5, 6))) instead, but it's still ugly. Hope this helps, Rui Barradas -- Este e-mail foi analisado pelo software antivírus AVG para verificar a presença de vírus. www.avg.com __ R-help@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.
Re: [R] if-else that returns vector
What a strange question... ifelse returns a vector (all data in R is vectors... some have length 1, but length zero is also possible, as are longer vectors) that is exactly as long as the logical vector that you give it, filled with elements from the respective positions in the vectors supplied in the second and third arguments. Because your logical vector is length 1, you only get a vector with the first element of the second argument. If you want to choose between one of two vectors considered wholly, then "if" is what you need: result <- if (TRUE) c(1,2,3) else c(5,6) On October 12, 2023 1:22:03 PM PDT, Christofer Bogaso wrote: >Hi, > >Following expression returns only the first element > >ifelse(T, c(1,2,3), c(5,6)) > >However I am looking for some one-liner expression like above which >will return the entire vector. > >Is there any way to achieve this? > >__ >R-help@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. -- Sent from my phone. Please excuse my brevity. __ R-help@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.
Re: [R] if-else that returns vector
how about if(T) c(1,2,3) else c(5,6) ? On 2023-10-12 4:22 p.m., Christofer Bogaso wrote: Hi, Following expression returns only the first element ifelse(T, c(1,2,3), c(5,6)) However I am looking for some one-liner expression like above which will return the entire vector. Is there any way to achieve this? __ R-help@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. __ R-help@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.
[R] if-else that returns vector
Hi, Following expression returns only the first element ifelse(T, c(1,2,3), c(5,6)) However I am looking for some one-liner expression like above which will return the entire vector. Is there any way to achieve this? __ R-help@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.
