[R] table function

[Marc Schwartz]

On Aug 24, 2009, at 10:59 AM, Inchallah Yarab wrote:

> hi,
>
> i want to use the function table to build a table not of frequence  
> (number of time the vareable is repeated in a list or a data  
> frame!!) but in function of classes
> I don t find a clear explnation in  examples of  ?table !!!
>
> example
>
> x      y        z
> 1    0       100
> 5    1       1500
> 6    1       1200
> 2    2       500
> 1    1       3500
> 5     2     2000
> 8     5     4500
>
> i want to do a table summerizing the number of variable where z is  
> in [0-1000],],[1000-3000], [> 3000]
>
> thank you very much for your help


See ?cut, which bins a continuous variable.

 > DF
   x y    z
1 1 0  100
2 5 1 1500
3 6 1 1200
4 2 2  500
5 1 1 3500
6 5 2 2000
7 8 5 4500


 > table(cut(DF$z, breaks = c(-Inf, 1000, 3000, Inf),
             labels = c("0 - 1000", ">1000 - 3000", ">3000")))

     0 - 1000 >1000 - 3000        >3000
            2            3            2

HTH,

Marc Schwartz