[R] how to find interval?

[PIKAL Petr]

Hi

I am not sure if my solution is general enough

diff(c(0,which(1:10 %in% c(3, 5, 6, 10))))
[1] 3 2 1 4

Regards
Petr


> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of gildororonar at mail-on.us
> Sent: Tuesday, September 17, 2013 12:15 PM
> To: r-help at r-project.org
> Subject: [R] how to find interval?
> 
> I can do this:
> 
> > 1:10 %in% c(3, 5, 6, 10)
>   [1] FALSE FALSE  TRUE FALSE  TRUE  TRUE FALSE FALSE FALSE  TRUE
> 
> but what I wish to get is:
> 
> [1] 3 2 1 4
> 
> let me explain:
> 
> 3 # [1:3] ends with TRUE, i.e. FALSE FALSE  TRUE
> 2 # [4:5] ends with TRUE, i.e. FALSE  TRUE
> 1 # [6:6] ends with TRUE, i.e. TRUE
> 4 # [7:10] ends with TRUE, i.e. FALSE FALSE FALSE TRUE
> 
> That is, %in% gave me a serial whether or not the element is in a set,
> the length is equal to the former, i.e. 1:10
> 
> But I wish to get a serial of intevals of occurance of the element in
> the set, the length is equal to the latter i.e. c(3, 5, 6, 10)
> 
> With ths task of finding the intervals, I found, with googling, a
> function called findInterval. I did read every line of that manual, and
> it seems to be for a completely different purpose.
> 
> Kindly help the poor newbie:)
> 
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