alt Hacker NewsHow useful is this when you are using numbers in a reasonable range, like 10^-12 to 10^12? Generally I try to scale my numbers to be in this range, whether by picking the right units or scaling constraints and objectives when doing nonlinear programming/ optimization.
Like looking at this example,
https://herbie.uwplse.org/demo/b070b371a661191752fe37ce0321c...
It is claimed that for the function f(x) =sqrt(x+1) -1
Accuracy is increased by from 8.5% accuracy to 98% for alternative 5 Which has f(x) = 0.5x
Ok so x=99, the right answer is sqrt(100) -1 = 9
But 0.5 * 99 = 49.5 which doesn't seem too accurate to me.
Replies
Check the specification at the top. The range for x is [-1, 1]. For the range you provided the accuracy of the 0.5x alternative is reported as only 33%: https://herbie.uwplse.org/demo/570b973df0f1f4a78fe791858038a...
The precondition on the link you shared has -1 <= x && x <= 1, so 99 is way outside of that range. But even so, testing for x=1, which is supposed to be inside that range, 0.5 doesn't seem tolerably close to 0.4142.