[R] high-dimensional contingency table

[David Winsemius]

On May 23, 2010, at 8:41 PM, Claudia Rodriguez wrote:

> Dear Friends.
> I am just starting to use R. And in this occasion I want to  
> construct a
> high-dimensional contingency table, because I want to crate a mosaic  
> plot
> with the vcd package.
> My table is in this format:
>
>    año ac.rep    cat.gru conteos
> 1  2005      R    parejas     253
> 2  2005      N    parejas      23
> 3  2006      R    parejas     347
> 4  2006      N    parejas      39
> 5  2007      R    parejas     266
> 6  2007      N    parejas      83
> 7  2005      R solitarios      53
> 8  2005      N solitarios       1
> 9  2006      R solitarios     109
> 10 2006      N solitarios       8
> 11 2007      R solitarios      85
> 12 2007      N solitarios      34
> 13 2005      R      trios      29
> 14 2005      N      trios       1
> 15 2006      R      trios      62
> 16 2006      N      trios      19
> 17 2007      R      trios      48
> 18 2007      N      trios       3
>
> How can I do this?
> I saw the help of the "mosaic" command, and I found that the files  
> are like
> a hig-dimensional contingency table (for example "Tytanic" data),  
> but I was
> unable to do the change.

mosaic's help page says you need to supply a data.frame or a  
contingency table. Given that you do not have separate records for  
each individual, but rather have counts in the last column, you can  
use xtabs to create a table object. Note the help page of xtabs says:

## xtabs() <-> as.data.frame.table()
You need to tell xtabs which column has the counts.

xtabs(conteos ~.,dta)
mosaic( cat.gru ~año, data = xtabs( conteos ~., dta))

-- 
David.

> Thank you very much!!!
> With best wishes
>
> -- 
> Claudia I. Rodríguez-Flores
> Maestra en Ciencias Biológicas
> Laboratorio de Ecología, UBIPRO
> UNAM FES-Iztacala
> 52-55-56231130


David Winsemius, MD
West Hartford, CT