Hi, This thread started because (...).next_prime() and next_prime(...) behave differently. So I assume this can be fixed immediately?
As to provable/probabilistic. I am worried about global modes since people will forget about them.... Michel On Jun 7, 8:19 pm, "William Stein" <[EMAIL PROTECTED]> wrote: > On 6/7/07, David Harvey <[EMAIL PROTECTED]> wrote: > > > > I agree too, though I think is_prime should remain provably correct. > > > I disagree. I think is_prime should have the same option available, > > and the default should be probabilistic. > > > The idea of these probabilistic tests is supposed to be that the > > probability of error is far less than the probability of error in > > your hardware (bounded uniformly, regardless of the input). Whether > > or not you are searching for the *next* prime or testing a *specific* > > value to be prime shouldn't affect your choice of algorithm. In the > > majority of applications the probabilistic test is the one a user > > would want, given the speed difference. > > No. Absolutely throughout SAGE I have in every possible case made > the choice proof=True the default, and here the intension for is_prime > is that proof=True be the default. I'm am deeply opposed to > having proof=False the default for any SAGE functions. However, > one of the SAGE Days 4 coding sprint projects is to implement an > easy-to-use global function "proof": > > def proof(on=True): > """ > proof(True) -- turns proof on globally by default > proof(False) -- turns proof off globally by default > """ > > The real work here is to retrofit every function in sage that has a proof= > option to now say "proof='default'" by default, which will then respect > the choice made by the proof command above. People could put proof(False) > in their init.sage if they are applied mathematicians... If you're claiming > a result for a paper, you definitely remark that you ran the computation > in SAGE after typing "proof(True)". > > I am not going to argue with David Harvey and others about specifically > whether the function is_prime should have proof=True or False by default. > I think the decision about the proof parameters for algorithms should > be a global decision -- i.e., have the default always be true or always be > false. In PARI, e.g., the default is always false. In MAGMA it is always > True (at least that's the goal). > > This uniformity should be throughout the system and should only be > invalidated when the function name specifically indicates it. E.g,. we should > add > is_probable_prime > and that would always have proof=False (it wouldn't even have a proof > parameter). > > William > > -- William --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
