[R] Sorting problem

[(Ted Harding)]

On 24-Dec-04 Gabor Grothendieck wrote:
> 
> From:   Paul JH Drake <p.drake at beatson.gla.ac.uk>
>> 
>> When I plot data as a boxplot, the boxes appear on the plot in
>> alphabetical order (of group) rather than the order in which they
>> appear
>> in the data. So far, the only thing I can do to fix this is to prefix
>> the group labels with a,b,c...etc to trick R into plotting them in the
>> right order.
>> 
>> Can sorting be turned off?
>> How should I address this sensibly?
> 
> Actually they are shown in order of the levels of the factor.
> e.g. to show them in reverse order:
> 
> attach(InsectSprays)
> spray <- factor( as.character(spray), level = rev(levels(spray)) )
> boxplot(count ~ spray)

Applying boxplot to data constructed as follows:

  X<-list(C=rnorm(10),B=rnorm(20),A=rnorm(30))
  boxplot(X)

gives the plots in the order "C", "B", "A", so here they indeed
come out in the order of the data.

But suppose I had wanted them in the order "B", "A", "C", say.
How would Gabor's suggestion (or similar) be applied to this case?
 
(OK I'm being thick, maybe; but I can't see how to relate the
one to the other!)

Ted.