[R] [FORGED] Re: Generate list if sequence form two vector element

[peter dalgaard]

There's also

mapply(a, b, FUN=seq, SIMPLIFY=FALSE)

(turn off simplication so that you don't unexpectedly get a matrix whenever all elements of results have same length. This also affects apply()-based solutions.)

...except that according to original spec, one should ensure a < b. So

myseq <- function(a,b) if(a<b) a:b else b:a
mapply(a, b, FUN=myseq, SIMPLIFY=FALSE)

-pd

> On 22 Jun 2016, at 10:42 , Jim Lemon <drjimlemon at gmail.com> wrote:
> 
> Now why didn't I think of that?
> 
> apply(matrix(c(a,b),ncol=2),1,function(x)x[1]:x[2])
> 
> Jim
> 
> On Wed, Jun 22, 2016 at 6:14 PM, Rolf Turner <r.turner at auckland.ac.nz> wrote:
>> On 22/06/16 20:00, Jim Lemon wrote:
>>> 
>>> Hi Tanvir,
>>> Not at all elegant, but:
>>> 
>>> make.seq<-function(x) return(seq(x[1],x[2]))
>>> apply(matrix(c(a,b),ncol=2),1,make.seq)
>> 
>> 
>> Not sure that this is more "elegant" but it's a one-liner:
>> 
>> lapply(1:length(a),function(i,a,b){a[i]:b[i]},a=a,b=b)
>> 
>> cheers,
>> 
>> Rolf
>> 
>> 
>>> On Wed, Jun 22, 2016 at 5:32 PM, Mohammad Tanvir Ahamed via R-help
>>> <r-help at r-project.org> wrote:
>>>> 
>>>> Hi,
>>>> I want to do the follow thing
>>>> 
>>>> Input :
>>>> a <- c(1,3,6,9)
>>>> 
>>>> 
>>>> b<-c(10,7,20,2)
>>>> 
>>>> 
>>>> Expected outcome :
>>>> 
>>>> d<-list(1:10,3:7,6:20,2:9)
> 
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-- 
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
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