[R] a way to control xlim in multhist?

[Justin Gengler]

Thanks in advance for any suggestions:

I am using the 'multhist' function in the 'plotrix' package to 
display histograms of some variable 'x' given some value of another 
variable 'z' -- for example, separate histograms for some variable 
according to sex (or another dichotomous) variable.  Thus I am using 
something like the following:

multhist(list(x[z==1],x[z==0]),...).

This generates histograms well enough, but because one cannot control 
the 'xlim' parameter the x-axis labels are very odd (or rather, 
strictly speaking, you CAN control it, but doing so does not change 
the x-axis value labels in the same way that it would if you were 
using the simple 'hist' command).  More specifically, the labels 
almost always seem to progress in increments of 5 or 0.5, depending 
on the scale (see, for example, this graph: 
http://addictedtor.free.fr/graphiques/RGraphGallery.php?graph=82). 
Moreover, if x is, say, a categorical variable with possible values 
of 1 through 5, the x-axis labels will remain in the base-5 form 
(e.g., 0.5, 1.5, 2.5, etc.) rather than taking on the various 
categorical values, regardless of any xlim specification.

I realize that the issue here is that multhist relies on the 
'barplot' function, so I have attempted to hack the xlim change 
there.  But no dice.

So the bottom line is: is there a way to control x-axis scale and 
labeling through xliim when using multhist?

Thanks,

Justin Gengler

Also: for a concrete demonstration of what I mean, compare the following:

#1

mh <- list(rnorm(200, mean=100, sd=10), rnorm(200, mean=100, sd=10))
multhist(mh)

#2

multhist(mh,xlim=c(0,20))