4 ms·
The issue here is that unless you have checks that your values dont over or underflow at every stage of the calculation, you can never actually know if your ans
by snovv_crash 7y ago
The issue here is that unless you have checks that your values dont over or underflow at every stage of the calculation, you can never actually know if your answers are accurate, even if they might be repeatable.
- tgflynn 7y agoI would think that in most cases you should be able to prove an upper bound on the sum and make sure the accumulator is large enough to accommodate it. My guess is that 512 bits should be enough to span all physically/computationally relevant scales.
- pascal_cuoq 7y agoThis article lists some real examples that require more than 512 bits: https://res.mdpi.com/d_attachment/mathematics/mathematics-03-00337/article_deploy/mathematics-03-00337.pdf https://res.mdpi.com/d_attachment/mathematics/mathematics-03... Note that digits of precision are expressed in decimal unless explicitly given as “bits”, so that the phrase “10,000-digit arithmetic” really means around 33,000 bits.
- tgflynn 7y agoCertainly if you have errors that grow exponentially all bets are off. I wouldn't think that would apply to simply summing a set of numbers though.