C Y wrote:
> --- Stavros Macrakis wrote:
>
>
>>The conversion of floats to fractions is controlled by the global
>>parameter ratepsilon. By default, this is 2.0e-8. I have argued for
>>a long time that this should be much smaller, perhaps 1.0e-15 (5
>>ulps).
>
>
> Are there any downsides anyone can see to this? If not, I move we
> change it pronto.
>
>
The downside to this is that the numerator and denominator sizes
of the arithmetic results from adding/multiplying,
etc the rational numbers grows, generally exponentially in the
number of operations. If you set ratepsilon to a very small quantity
then there is a danger that some computations will get slower, sooner.
If ratepsilon is set to a small multiple of double-float-epsilon, I
won't argue, but you asked... what was the downside.
RJF