Here's an extensive discussion on comparing floats: http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm
Garth On 08/07/11 11:44, Garth N. Wells wrote: > > > On 08/07/11 11:33, Martin Sandve Alnæs wrote: >> I already explained this, but let me make it clearer: >> >> If >> x >> eps, >> such that >> x + eps == x, >> then near(x, x) implemented as >> x < x + eps >> will be equivalent to >> x < x >> which is false. >> > > eps should be scaled. > >> Clearly, near(x,x) should always be true in a correct implementation. >> Using x <= x + eps fixes this. This is not "relying on equality", >> that would be using ==. >> >> If you have a failing test case, show it to me and I will see what I can do. >> > > See buildbot. > > Garth > >> Martin >> >> >> On 8 July 2011 12:21, Garth N. Wells <gn...@cam.ac.uk> wrote: >>> I think that this is a 'bug' in the test. Relying on equality (i.e. <= >>> versus <) for non-integers will lead to problems somewhere (like the >>> 32-bit buildbot failing). >>> >>> Garth >>> >>> >>> On 08/07/11 09:23, nore...@launchpad.net wrote: >>>> ------------------------------------------------------------ >>>> revno: 6054 >>>> committer: Martin Alnes <marti...@simula.no> >>>> branch nick: work >>>> timestamp: Fri 2011-07-08 10:20:54 +0200 >>>> message: >>>> Re-introduce bugfix in near after recent mistaken(?) re-introduction of >>>> the bug, or something... Also disable debug print in test. >>>> modified: >>>> dolfin/math/basic.cpp >>>> test/unit/math/python/basic.py >>>> >>>> >>>> -- >>>> lp:dolfin >>>> https://code.launchpad.net/~dolfin-core/dolfin/main >>>> >>>> Your team DOLFIN Core Team is subscribed to branch lp:dolfin. >>>> To unsubscribe from this branch go to >>>> https://code.launchpad.net/~dolfin-core/dolfin/main/+edit-subscription >>> >>> _______________________________________________ >>> Mailing list: https://launchpad.net/~dolfin >>> Post to : dolfin@lists.launchpad.net >>> Unsubscribe : https://launchpad.net/~dolfin >>> More help : https://help.launchpad.net/ListHelp >>> > > > _______________________________________________ > Mailing list: https://launchpad.net/~dolfin > Post to : dolfin@lists.launchpad.net > Unsubscribe : https://launchpad.net/~dolfin > More help : https://help.launchpad.net/ListHelp _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : dolfin@lists.launchpad.net Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
