[R] Polytonic Vector Analysis

I'm looking for an R package to do Polytopic Vector Analysis (PVA) without success. I've checked CRAN, then did a site searched there, scanned the packages list, looked over old Help posting (there was a query about the same back in 2005 or so - only one response that didn’t give much direction

[R] R graphical question

I'm trying to create a graph using plot() with an axis that I essentially want to plot the categories in the reverse alphanumeric order - opposite of the typical R fashion. Is there a function to do this? In other words, I have categories "a", "c", "g", "z" which is the order they'll be plo