R devel - Jan 2004 - stem plot problem with the mtcars data (PR#6453)

Full_Name: Liming Liang
Version: 1.8.1
OS: windows2000 professional
Submission from: (NULL) (67.172.81.139)


I was looking at the variable 'mpg' of the data file 'mtcars'
and make a stem
plot, the following is the commend I entered. The stem plot shows the largest
observation is 32.9 but actually in the data the largest observation is 33.9,
here might be a problem.
> data(mtcars)
> stem(mtcars$mpg)
  The decimal point is at the |

  10 | 44
  12 | 3
  14 | 3702258
  16 | 438
  18 | 17227
  20 | 00445
  22 | 88
  24 | 4
  26 | 03
  28 | 
  30 | 44
  32 | 49
> mtcars$mpg
 [1] 21.0 21.0 22.8 21.4 18.7 18.1 14.3 24.4 22.8 19.2 17.8 16.4 17.3 15.2 10.4
[16] 10.4 14.7 32.4 30.4 33.9 21.5 15.5 15.2 13.3 19.2 27.3 26.0 30.4 15.8 19.7
[31] 15.0 21.4
> max(mtcars$mpg)
[1] 33.9

Liming Liang
Dept of Statistics and Probability
Michigan State University

lianglim@stt.msu.edu writes:
> Full_Name: Liming Liang
> Version: 1.8.1
> OS: windows2000 professional
> Submission from: (NULL) (67.172.81.139)
> 
> 
> I was looking at the variable 'mpg' of the data file
'mtcars' and make a stem
> plot, the following is the commend I entered. The stem plot shows the
largest
> observation is 32.9 but actually in the data the largest observation is
33.9,
> here might be a problem.
> 
> > data(mtcars)
> > stem(mtcars$mpg)
> 
>   The decimal point is at the |
> 
>   10 | 44
>   12 | 3
>   14 | 3702258
>   16 | 438
>   18 | 17227
>   20 | 00445
>   22 | 88
>   24 | 4
>   26 | 03
>   28 | 
>   30 | 44
>   32 | 49
Actually it is showing the largest value as either 32.9 or 33.9.
Notice that the stem is being incremented by 2, in which case the
leaf can be ambiguous.