[R] boxplot via plot command

[Ken Knoblauch]

Hi,
Antje <niederlein-rstat <at> yahoo.de> writes:
> 
> Hi folks,
> 
> I've just discovered that the following code leads to boxplot 
> (surprisingly to me).
> Can anybody explain to me why? Is this documented somewhere? I've never 
> consider this option before.
> 
> x <- rnorm(300)
> l <- c(rep("label1",100), rep("label2",50), rep("label3",150))
> 
> df <- data.frame(as.factor(l), x)
> plot(df)
> 
> Thank you!
> Antje
> 
You can follow this through the various methods.  If you look
at plot.data.frame  

getAnywhere(plot.data.frame)  

You'll see that when the data.frame has only 2 columns, it
calls plot with the first two arguments.  Since the first argument
here is a factor, it dispatches to the plot.factor method

getAnywhere(plot.factor)

from which you'll see that under your circumstances it will call 
boxplot

HTH,

Ken