On 9/25/2011 1:21 AM, Steven D'Aprano wrote:
Terry Reedy wrote:
On 9/24/2011 9:53 AM, Steven D'Aprano wrote:
[...]
[0.0 + i*width for i in range(8)]
[0.0, 0.3, 0.6, 0.8999999999999999, 1.2, 1.5, 1.7999999999999998, 2.1]
The 4th and 7th values have rounding errors, the rest are exact
No they are not. Their errors are just smaller and not visible with 16
digits.
Pardon. I meant that they were as close to exact as is possible in binary
floats. With the exception of 0.8999... and 1.7999... I don't believe any
other float can be closer to the exact value.
I did mention that "If the exact value isn't representable as a float, I'm
okay with returning the nearest possible float." :)
I do hope you did not stop with my lead-in sentence, and read to the
end, where I gave you most of the answer you were looking for, without
using the fractions module.
--
Terry Jan Reedy
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