[Rd] cut takes long time

[Gabor Grothendieck]

The following cut command takes nearly 10 seconds on my machine even
though the length of input vector is only 6.  I am running on Windows
Vista with C2D BLAS using R 2.11.1.  Using the default BLAS and either
R 2.10.1 or "R version 2.12.0 Under development (unstable) (2010-05-31
r52164)" also gives me results in the 9-11 second range.
I would have expected it to take much less time.


tt <- structure(c(631206000, 631206060, 631206180, 631206240, 631206300,
978224400), class = c("POSIXt", "POSIXct"), tzone = "")

system.time(cut(tt, "2 hours", include = TRUE)) # 9.45  0.01  9.58


R.version.string # "R version 2.11.1 Patched (2010-05-31 r52167)"
win.version() #  "Windows Vista (build 6002) Service Pack 2"