CODEWITHSUNDEEP
rcontingency
tomw
tomw

Reputation: 3158

Specifying a proportion in a nested table in prop.table

I make a four way table with xtabs

library(magrittr)
xtabs( ~ vs + gear + cyl, data = mtcars) %>% 
  ftable(row.vars = "gear")

returns 

     vs   0        1      
     cyl  4  6  8  4  6  8
gear                      
3         0  0 12  1  2  0
4         0  2  0  8  2  0
5         1  1  2  1  0  0

Now I want proportions within levels of mtcars$vs.

If I use prop.table

xtabs( ~ vs + gear + cyl, data = mtcars) %>% 
  ftable(row.vars = "gear") %>% 
  prop.table(margin = 1) %>% 
  round(2)

I get

     vs     0              1          
     cyl    4    6    8    4    6    8
gear                                  
3        0.00 0.00 0.80 0.07 0.13 0.00
4        0.00 0.17 0.00 0.67 0.17 0.00
5        0.20 0.20 0.40 0.20 0.00 0.00

Ie--I want the entry for vs == 0, gear == 3, cyl == 8, to be 1.00

Upvotes: 0

Views: 247

Answers (1)

Viviana B. Lencina
Viviana B. Lencina

Reputation: 21

Try this

 xtabs( ~ vs + gear + cyl, data = mtcars) %>% 
   ftable(row.vars = c("gear","vs")) %>% 
   prop.table(margin = 1) %>% 
   round(2)

the results are

        cyl    4    6    8
gear vs                   
3    0      0.00 0.00 1.00
     1      0.33 0.67 0.00
4    0      0.00 1.00 0.00
     1      0.80 0.20 0.00
5    0      0.25 0.25 0.50
     1      1.00 0.00 0.00

Upvotes: 2

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