I try to type this in my R-winEdt.
but I got these. Do you know?
Aimin
 > 
install.packages('http://rh-mirror.linux.iastate.edu/CRAN/bin/windows/contrib/2.4/plotrix_2.1-6.zip')
Warning in download.packages(pkgs, destdir = tmpd, available = available,  :
          no package 
'http://rh-mirror.linux.iastate.edu/CRAN/bin/windows/contrib/2.4/plotrix_2.1-6.zip' 
at the repositories