[Rd] biplot() does work for prcomp objects (PR#6425)

[litwilljeff at yahoo.com]

Full_Name: Jeff Litwiller
Version: 1.8.1
OS: Windows 2000
Submission from: (NULL) (192.160.186.181)


biplot() does not work on objects of mode prcomp.  Even though the documentation
and release notes indicate that it should.

To get biplot() to work on prcomp objects I had to do the following:

1) Add the following line to "R\rw1081\library\mva\NAMESPACE":

S3method(biplot, prcomp)

2) Make the following change to "\R\rw1081\library\mva\R\mva":

change "x$loadings" to "x$rotation"

Note, the same fixes needed to be applied to 1.8.0.