G'day all.

Quoting "Mitchell, Neil" <[EMAIL PROTECTED]>:

With rounding to the nearest even integer for 0.5's you get 6, otherwise
if you always round up you get 7. If you bias towards rounding up you
get a general upwards trend as numbers are rounded, which is bad, while
the even condition ensures that statistically it averages to the same
thing.

There are also many numeric algorithms for which the rounding pattern
in the least-significant digit is somewhat systematic.  A simple example
might be this:

x <- round(x + 0.5)
x <- round(x - 0.5)
x <- round(x + 0.5)
x <- round(x - 0.5)
... etc

If you try this procedure starting with, say, x = 1.5, you can see a
clear difference between round-up and round-to-even.  With round-up,
the rounding error is keeps increasing as the procedure continues.  With
round-to-even, the error is bounded.

Cheers,
Andrew Bromage
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