[SMIL30 LC comment] rounding in 17.4.4 and 19.4.4
"Dr. Olaf Hoffmann" <[email protected]>
| Newsgroups | gmane.comp.web.smil |
|---|---|
| Organization | Atomare Prozesse - Universität Hannover |
| Message-ID | <[email protected]> |
Hello SMIL working group, this does not look like an accurate method to round: 'The mathematical definition of rounding is: coerced-integer-value = Math.floor( interpolated-value + 0.5 )' -> There are different mathematical definitions for rounding. This is a biased rounding because number=integer+0.5 is always rounded up (for other cases the rounding definitions are the same). This is not an accurate rounding method. This means, over a larger number of rounding the average rounding error is not zero. For an unbiased rounding, for example for even integers number is rounded down, for odd up... example: value, top eq. 'rounding' , unbiased rounding (round to even) 0.5 1 0 1.5 2 2 2.5 3 2 3.5 4 4 4.5 5 4 5.5 6 6 6.5 7 6 7.5 8 8 8.5 9 8 9.5 10 10 average 5 5.5 5 I would like to suggest to use the unbiased or 'round to even' method ...