Ok, thank you for your guidelines. Additionally, I have had to put the
biplotes.princomp function in the first place of the script, just after
biplotes <- function(x, ...) UseMethod("biplotes"). By doing this it works,
althrough I don?t really know why. I hope to acquire higher skills in R
programming soon, there are still many things of R that I do not handle at
this time.
Thanks again.