R help - May 2020 - possible issue with scatterplot function in car package

library (car)

 aa <- data.frame(x=c(2,  5, 6, 7, 8),
+  y=c(5,  10, 9, 12, 11),
+ ch=c("N",  "Q", "R", "S",
"T"),
+ stringsAsFactors=FALSE)

scatterplot(aa$x,aa$y,smooth = FALSE, grid = FALSE, frame = FALSE,regLine=F)

Both x and y boxplots are correct
and in particular the median of the x box is at 6 which is confirmed
> median(aa$x)
[1] 6

Now I do only one addition to the scatterplot: I add
xlim
> scatterplot(aa$x,aa$y,smooth = FALSE, grid = FALSE, frame
FALSE,regLine=F,xlim=c(0,8))
This causes the boxplot on x-axis to be in error:
1) the lower whisker starts now from zero
2) the median is between 4 and 6 and no longer at 6 as before
> sessionInfo()
R version 3.6.3 (2020-02-29)
 [1] car_3.0-7

	[[alternative HTML version deleted]]

On 3/05/20 11:30 am, Yousri Fanous wrote:
> library (car)
> 
>   aa <- data.frame(x=c(2,  5, 6, 7, 8),
> +  y=c(5,  10, 9, 12, 11),
> + ch=c("N",  "Q", "R", "S",
"T"),
> + stringsAsFactors=FALSE)
> 
> scatterplot(aa$x,aa$y,smooth = FALSE, grid = FALSE, frame =
FALSE,regLine=F)
> 
> Both x and y boxplots are correct
> and in particular the median of the x box is at 6 which is confirmed
> 
>> median(aa$x)
> [1] 6
> 
> Now I do only one addition to the scatterplot: I add xlim
>> scatterplot(aa$x,aa$y,smooth = FALSE, grid = FALSE, frame >
FALSE,regLine=F,xlim=c(0,8))
> 
> This causes the boxplot on x-axis to be in error:
> 1) the lower whisker starts now from zero
> 2) the median is between 4 and 6 and no longer at 6 as before
> 
>> sessionInfo()
> R version 3.6.3 (2020-02-29)
>   [1] car_3.0-7
(1) Please present data using dput(); this makes life a lot easier for 
your respondents.  (See posting guide.)

(2) Please do not post in html.  (See posting guide.)

(3) I agree that this looks like a bug.

(4) Email about issues like this should be sent to the maintainer of the 
package in question (see maintainer("car")) and not to r-help.

cheers,

Rolf Turner

-- 
Honorary Research Fellow
Department of Statistics
University of Auckland
Phone: +64-9-373-7599 ext. 88276