[R] adjusting x-axis labels

[Adrienne Keller]

I am trying to tweak how my categorical x-axis labels are formatted in  
my bar graph. Specifically, I would like to a) decrease the spacing  
between lines (e.g. spacing between Dialium and guianensis)  b) right  
justify the text and c) have each species name align with the center  
of the corresponding bar graph.

A simplified version of my code thus far is as follows. I am using  
RStudio v. .94.84

install.packages('gplots')
library(gplots)
x<-rnorm(9, mean=600, sd=300)
speciesnames<-c("Dialium\nguianensis", "Inga\nalba", "Tachigali 
\nversicolor", "Brosimum\nutile", "Caryocar\ncostaricense", "Castilla 
\ntunu", "Otoba\nnovagranatensis", "Pourouma\nbicolor", "Socratea 
\nexorrhiza")
xvals<-barplot2(x, ylab=expression(plain("Soil acid phosphatase  
activity")~(nmol~h^{-1}*g^{-1})), ylim=c(0,1200), cex.axis=0.6)
text(xvals,par("usr")[3]-115, srt=45,adj=c(0.5,0),  
labels=speciesnames, cex=.6, xpd=T)

Any suggestions to help solve these problems would be greatly  
appreciated. I am new to working with graphics in R.

Thanks,

Adrienne Keller
Graduate Student, College of Forestry
University of Montana
adrienne.keller at umontana.edu
(Phone) 651-485-5822