Description: calc doe's some 'tie to zero' rounding, acc. @erAck intended for integer values but imho affecting all calculations, this rounding sometimes has evil effects, e.g. '=(2^53+31-2^53)+(2^53-31-2^53)+(2^53+31-2^53)+(2^53-31-2^53)' should mathematical result in '0' (the subterms in brackets cancel each other out), 'fp-math' calculates '2' because above 2^53 IEEE 754 is limited to the 'even integers' and some small rounding steps in, calc calculates '64' reg. unneccessary rough rounding and either different effect of it below and above a magnitude range border (2^53), or different effect for '+' vs. '-', Steps to Reproduce: 1. calculate '=(2^53+31-2^53)+(2^53-31-2^53)+(2^53+31-2^53)+(2^53-31-2^53)' 2. 3. Actual Results: 64 Expected Results: '0' or maximal tolerable '2', Reproducible: Always User Profile Reset: No Additional Info: Version: 7.1.0.0.alpha1+ (x64) Build ID: b61bf7c7cfcf97a5ade6d130873af146670bc2ee CPU threads: 8; OS: Windows 6.1 Service Pack 1 Build 7601; UI render: default; VCL: win Locale: de-DE (de_DE); UI: en-US Calc:
(In reply to b. from comment #0) > calc doe's some 'tie to zero' rounding, acc. @erAck intended for integer > values but imho affecting all calculations, I never said the tie to zero was intended for integer values. Otherwise agree, that should be reworked.
hello @erAck, sorry, maybe i (or you?) was lost in the nested 'non' and 'not's of: 'Anyway, you hit an effect of the approxAdd() function used to normally eliminate accuracy limitations when adding/subtracting not non-ambiguous representable integer values with opposite signs of similar magnitudes by scaling to 2^-48 and thus rounding off the least significant 4 bits to yield a result of 0.0, i.e. to let 0.3-0.2-0.1==0.0.', cited acc. https://ask.libreoffice.org/en/question/274247/calc-wrong-calculation-would-like-a-recheck/,
Dear b., To make sure we're focusing on the bugs that affect our users today, LibreOffice QA is asking bug reporters and confirmers to retest open, confirmed bugs which have not been touched for over a year. There have been thousands of bug fixes and commits since anyone checked on this bug report. During that time, it's possible that the bug has been fixed, or the details of the problem have changed. We'd really appreciate your help in getting confirmation that the bug is still present. If you have time, please do the following: Test to see if the bug is still present with the latest version of LibreOffice from https://www.libreoffice.org/download/ If the bug is present, please leave a comment that includes the information from Help - About LibreOffice. If the bug is NOT present, please set the bug's Status field to RESOLVED-WORKSFORME and leave a comment that includes the information from Help - About LibreOffice. Please DO NOT Update the version field Reply via email (please reply directly on the bug tracker) Set the bug's Status field to RESOLVED - FIXED (this status has a particular meaning that is not appropriate in this case) If you want to do more to help you can test to see if your issue is a REGRESSION. To do so: 1. Download and install oldest version of LibreOffice (usually 3.3 unless your bug pertains to a feature added after 3.3) from https://downloadarchive.documentfoundation.org/libreoffice/old/ 2. Test your bug 3. Leave a comment with your results. 4a. If the bug was present with 3.3 - set version to 'inherited from OOo'; 4b. If the bug was not present in 3.3 - add 'regression' to keyword Feel free to come ask questions or to say hello in our QA chat: https://web.libera.chat/?settings=#libreoffice-qa Thank you for helping us make LibreOffice even better for everyone! Warm Regards, QA Team MassPing-UntouchedBug
result still 64 with ver.: Version: 24.2.5.2 (X86_64) / LibreOffice Community Build ID: 420(Build:2) CPU threads: 8; OS: Linux 6.8; UI render: default; VCL: x11 Locale: en-US (en_US.UTF-8); UI: en-US Debian package version: 4:24.2.5-4 Calc: threaded