Re: Re: Re: Using (s)printf()

[Anonymous Monk]

Actually, this isn't quite the whole story. Most everyone follows the IEEE convention of "round towards nearest or even."
Examples (rounding all of these to the one's place):

2.51 becomes 3 (this is the 'nearest' rule, which always comes first)
2.49 becomes 2 (again, 'nearest')

However, what happens if you have 2.50 ? Which way do you round it... 'tis no nearer to 2 than to 3. The IEEE standard says if there is a tie, round to the even number.

2.50 becomes 2
3.50 becomes 4

You have to pick up or down... this method is consistent and thus tends to make your errors (statistically) smaller.

[Hofmator]

Actually, this isn't quite the whole story. Most everyone follows the IEEE convention of "round towards nearest or even."

I'm aware of that - but it wasn't applicable in this case. Btw, (s)printf doesn't seem to get it right:

printf "%.15f", 0.5;  # prints 0.500000000000000
printf "%.0f",  0.5;  # prints 1 and should print 0

and 0.5 can be represented exactly ...

-- Hofmator