[R] Cairo package, png files within for loop are black?

[Douglas M. Hultstrand]

Hello,

I am generating .png images using the Cairo package in a for loop 
(looping on the number of zones, number of zones equals the number of 
plots to create based on different zone data).   When  I run the R 
script the .png files are created but they are all black?  If I comment 
out the for loop and force my zones to equal one the png file is created 
correctly?  Is there an issue with generating .png files within a for loop?

Create .png commands within for loop:

CairoPNG(paste(t.g), width=800, height=600, pointsize=12, bg="white")
    xyplot(areasqmi ~ value, x.p, groups=dur,
    main=(t.n), ylab=expression("Area(mi" ^ 2 * ")"),
    xlab="Maximum Average Depth of Percipitation (inches)",
    scales=list(y=list(log=TRUE)), ylim=c(1,1000000), type='l',
    auto.key=list(space='right'))
dev.off()

-- 
---------------------------------
Douglas M. Hultstrand, MS
Senior Hydrometeorologist
Metstat, Inc. Windsor, Colorado
voice: 970.686.1253
email: dmhultst at metstat.com
web: http://www.metstat.com