[R] counting the frequencies of a vector

[David Winsemius]

On Oct 16, 2008, at 12:55 PM, Jorge Ivan Velez wrote:

> Dear Jörg,
> See ?cut and ?table. Is this what you want?
>
> x <- c(1, 3, 1.2, 5, 5.9)
> table(cut(x,breaks=c(0,2,4,6)))
> (0,2] (2,4] (4,6]
>    2     1     2

Perhaps even greater future efficiency could be had by also adding

?seq

table(cut(x, breaks=seq(0, 6, by=2)))

A couple more keysrokes in this toy example but scales up much better  
to the requested purpose of evenly divided interval.

The OP should also note carefully the open aspect on the left of these  
intervals. That can be controlled with option in cut:

 > x <- c(1, 3, 1.2, 5, 5.9, 6)
 > table(cut(x, breaks=seq(0,6,by=2)))

(0,2] (2,4] (4,6]
     2     1     3
 > x <- c(1, 3, 1.2, 4, 5, 5.9, 6)
 > table(cut(x, breaks=seq(0,6,by=2)))

(0,2] (2,4] (4,6]
     2     2     3

 > table(cut(x, breaks=seq(0,6,by=2), right=FALSE))

[0,2) [2,4) [4,6)
     2     1     3

-- 
David Winsemius
Heritage Labs

>
>
> HTH,
>
> Jorge
>
>
> On Thu, Oct 16, 2008 at 12:46 PM, Jörg Groß <joerg at licht-malerei.de>  
> wrote:
>
>> Hi,
>>
>>
>> Is there a function which counts the frequencies of the occurence  
>> of a
>> number within an interval?
>>
>> for example I have this vector:
>>
>> x <- c(1, 3, 1.2, 5, 5.9)
>>
>> and I want a vector that gives me the frequencies within an  
>> interval of 2,
>> beginning at 0
>> (so the intervals are 0-2, 2-4, 4-6 and so on)
>>
>> so I get these frequencies:
>>
>> 2, 1, 2
>>
>>
>> Which functions do I have to use for this purpose?
>>
>> ______________________________________________
>> 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.
>>
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> 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.