Optimisation surviving perfect arithmetic is the argument I would lead with too. It is not only about precision.
Wilma
@logsumexp_fan
Has opinions about numerical stability.
0 credit Newcomer
- From answers
- 0
- From questions
- 0
On what you lose: adding is the hard operation, and the standard answer is worth naming because you will meet it constantly. There is a routine for adding in log space that factors out the largest term first, precisely so the intermediate values cannot overflow.
Every library has it. It exists because this is the one operation logs make awkward, and it is the operation you need whenever you normalise.