Plotting Factors -- Sorting x-axis

-----Original Message-----
From: r-help-bounces at stat.math.ethz.ch 
[mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Ko-Kang 
Kevin Wang
Sent: Tuesday, April 22, 2003 9:57 PM
To: R Help
Subject: [R] Plotting Factors -- Sorting x-axis


Hi,

Say I have a factor with 20-levels: 1, 2, 3, ..., 20, called foo.

If I do 
 plot(foo)
it will draw a barplot.  But the x-axis is sorted 
alphanumerically, i.e. 
1, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 2, 3, ..., 9, which 
is not what 
I want.  I'd like to x-axis to be in the order of 1 ~ 20 
numerically.  So, 
the question is, how do I change the order on the x-axis in this

-- 
Cheers,

Kevin

x <- factor(as.character(1:20))
x

x <- factor(x, levels = sort(as.numeric(x)))
x