R help - Sep 2008 - A problem about the color of symbols exceeding the coordinate limits

Hi all,

I don't know whether this is a bug in the function symbols(): when I
use semi-transparency for the background color in the symbols plot,
the colors of symols which exceed the coordinates limits will be lost
(i.e. the symbols will be blank). For example:
> symbols(1:5, 1:5, 1:5, bg = rgb(0, 0, 0, 0.5), xlim = c(1, 4.5))
The 5th circle has no color filled.
> sessionInfo()
R version 2.7.2 (2008-08-25)
i386-pc-mingw32

locale:
LC_COLLATE=Chinese_People's Republic of
China.936;LC_CTYPE=Chinese_People's Republic of
China.936;LC_MONETARY=Chinese_People's Republic of
China.936;LC_NUMERIC=C;LC_TIME=Chinese_People's Republic of China.936

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

Thanks!

Regards,
Yihui
-- 
Yihui Xie <xieyihui at gmail.com>
Phone: +86-(0)10-82509086 Fax: +86-(0)10-82509086
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Renmin University of China, Beijing, 100872, China