Launchpad has imported 8 comments from the remote bug at https://bugs.freedesktop.org/show_bug.cgi?id=37923.
If you reply to an imported comment from within Launchpad, your comment will be sent to the remote bug automatically. Read more about Launchpad's inter-bugtracker facilities at https://help.launchpad.net/InterBugTracking. ------------------------------------------------------------------------ On 2011-06-04T07:57:28+00:00 Christopher M. Penalver wrote: Created attachment 47525 openoffice.summation.bug.ods Downstream bug may be found at: https://bugs.launchpad.net/ubuntu/+source/libreoffice/+bug/340051 1) lsb_release -rd Description: Ubuntu 11.04 Release: 11.04 2) apt-cache policy libreoffice-calc libreoffice-calc: Installed: 1:3.3.2-1ubuntu5 Candidate: 1:3.3.2-1ubuntu5 Version table: *** 1:3.3.2-1ubuntu5 0 500 http://us.archive.ubuntu.com/ubuntu/ natty-updates/main i386 Packages 100 /var/lib/dpkg/status 1:3.3.2-1ubuntu4 0 500 http://us.archive.ubuntu.com/ubuntu/ natty/main i386 Packages 3) What is expected to happen in LibreOffice Calc via the Terminal: cd ~/Desktop && wget https://bugs.launchpad.net/ubuntu/+source/libreoffice/+bug/340051/+attachment/486207/+files/openoffice.summation.bug.ods && localc openoffice.summation.bug.ods is that cell A1=806515533049393 cell B1=1 cell C1=806515533049393 and cell D1=A1-B1-C1=-1. 4) What happens instead is cell D1 is 0. Reply at: https://bugs.launchpad.net/ubuntu/+source/openoffice.org/+bug/340051/comments/3 ------------------------------------------------------------------------ On 2011-06-04T08:40:19+00:00 Markus Mohrhard wrote: Hello Christopher, this is not a bug but a mathematical problem. Subtracting two nearly identical numbers is an ill-conditioned problem.http://en.wikipedia.org/wiki/Condition_number It's problem that every program using floating point numbers has and that can't really be solved. Reply at: https://bugs.launchpad.net/ubuntu/+source/openoffice.org/+bug/340051/comments/4 ------------------------------------------------------------------------ On 2011-06-04T09:47:02+00:00 Christopher M. Penalver wrote: (In reply to comment #1) > Hello Christopher, > > this is not a bug but a mathematical problem. Subtracting two nearly identical > numbers is an ill-conditioned > problem.http://en.wikipedia.org/wiki/Condition_number > > It's problem that every program using floating point numbers has and that > can't > really be solved. Markus, thank you for quickly taking a look at this. It is agreed this issue is not an easy one to deal with, and more an issue of "how accurate is it?" versus "is it 100% accurate or not?". However, this was marked as a bug because both Excel and Gnumeric correctly yield -1. Looks like a great opportunity to improve LO! :) Reply at: https://bugs.launchpad.net/ubuntu/+source/openoffice.org/+bug/340051/comments/5 ------------------------------------------------------------------------ On 2011-06-04T14:04:53+00:00 Markus Mohrhard wrote: Hello Christopher, sure it's annoying but if you try with for example Excel the limit is just a bit higher. Try with 1126515533121300 and 1. I'm really surprised that we have this problem a bit earlier but I don't think it is something we should worry about. There is no real possibility to resolve the general problem. So in my opinion this is annoying but we should not try to fix it. The only solution would be to use exact numbers instad of floating point numbers, but this will have even bigger performance impact. Reply at: https://bugs.launchpad.net/ubuntu/+source/openoffice.org/+bug/340051/comments/6 ------------------------------------------------------------------------ On 2011-06-04T23:10:51+00:00 Christopher M. Penalver wrote: (In reply to comment #3) > Hello Christopher, > > sure it's annoying but if you try with for example Excel the limit is just a > bit higher. Try with 1126515533121300 and 1. I'm really surprised that we have > this problem a bit earlier but I don't think it is something we should worry > about. Markus, thank you for your discussion on this issue. As I have been focused on upstreaming Ubuntu bugs, my standard for downstream triaging has been "What occurs in Excel in the same circumstance?" Viewing it this way, ones expectation for this issue is that LO, at least, matches the precision of Excel. Anything more precise than Excel, at best, is an ENHANCEMENT request. > There is no real possibility to resolve the general problem. So in my opinion > this is annoying but we should not try to fix it. > > The only solution would be to use exact numbers instad of floating point > numbers, but this will have even bigger performance impact. Regarding exact numbers v. floating point this is outside my area of expertise so I defer to your and the communities position as to if, how, and when to move forward on that. Reply at: https://bugs.launchpad.net/ubuntu/+source/openoffice.org/+bug/340051/comments/7 ------------------------------------------------------------------------ On 2011-06-18T14:17:19+00:00 Wope-1 wrote: @christopher: this is not a bug, as markus wrote @markus: before excel perform the calculation, it sort the numbers from highest to lowest. This may be enhancement. Reply at: https://bugs.launchpad.net/ubuntu/+source/openoffice.org/+bug/340051/comments/8 ------------------------------------------------------------------------ On 2011-06-18T21:33:09+00:00 Christopher M. Penalver wrote: wope, as per my last comment, this is considered a bug for Excel calculation expectation compatibility. Reply at: https://bugs.launchpad.net/ubuntu/+source/openoffice.org/+bug/340051/comments/9 ------------------------------------------------------------------------ On 2011-06-23T19:58:14+00:00 Markus Mohrhard wrote: @wope: then you run in other situations into the same problem, there is no solution to this problem, it's still strange that it happens a bit earlier than in excel but that may be due to some conversions in uno @christopher I still don't think that this is really a bug, we just behave a bit different than excel. I suppose there will always be some differences between calc and excel and not all are bugs. I lowered the importance a bit but you might try to convice Kohei or Rainer that it's more important. I won't close it but I don't think that we should do anything here. Reply at: https://bugs.launchpad.net/ubuntu/+source/openoffice.org/+bug/340051/comments/10 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/340051 Title: [upstream] Calc precision error subtracting 3 integers To manage notifications about this bug go to: https://bugs.launchpad.net/df-libreoffice/+bug/340051/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
