[R] c(1:n, 1:(n-1), 1:(n-2), ... , 1)

Achim Zeileis Achim.Zeileis at uibk.ac.at
Thu Sep 17 20:40:49 CEST 2015


On Thu, 17 Sep 2015, Peter Langfelder wrote:

> Not sure if this is slicker or easier to follow than your solution,
> but it is shorter :)
>
> do.call(c, lapply(n:1, function(n1) 1:n1))

Also not sure about efficiency but somewhat shorter...
unlist(lapply(5:1, seq))

> Peter
>
> On Thu, Sep 17, 2015 at 11:19 AM, Dan D <ddalthorp at usgs.gov> wrote:
>> Can anyone think of a slick way to create an array that looks like c(1:n,
>> 1:(n-1), 1:(n-2), ... , 1)?
>>
>> The following works, but it's inefficient and a little hard to follow:
>> n<-5
>> junk<-array(1:n,dim=c(n,n))
>> junk[((lower.tri(t(junk),diag=T)))[n:1,]]
>>
>> Any help would be greatly appreciated!
>>
>> -Dan
>>
>>
>>
>> --
>> View this message in context: http://r.789695.n4.nabble.com/c-1-n-1-n-1-1-n-2-1-tp4712390.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
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>
> ______________________________________________
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> and provide commented, minimal, self-contained, reproducible code.
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