Description: I tried to use the solver on the following model: 1*x1 + 2*x2 <= 6 1*x1 + 2*x2 >= 8 optimize for maximum of x1 + x2 The LibreOffice Linear Solver correctly identifies the model as infeasible, the LibreOffice CoinMP Linear Solver falsely finds the optimum x1=0 x2=3 which violates the second inequality. I would like upload the document, but I can't seem to figure out how to attach a file. Steps to Reproduce: 1. Create the following model: 1*x1 + 2*x2 <= 6 1*x1 + 2*x2 >= 8 optimize for maximum of x1 + x2 2. Use the solve with the LO Linear Solver -> model is infeasible (correct) 3. Use the solve with the LO CoinMP Linear Solver -> x1=0; x2=3 (incorrect) Actual Results: LO Linear Solver: model is infeasible (correct) LO CoinMP Linear Solver: x1=0; x2=3 (incorrect) Expected Results: Both solvers should recognize the model as infeasible Reproducible: Always User Profile Reset: No Additional Info: Version: 7.6.4.1 (X86_64) / LibreOffice Community Build ID: e19e193f88cd6c0525a17fb7a176ed8e6a3e2aa1 CPU threads: 8; OS: Linux 6.6; UI render: default; VCL: gtk3 Locale: en-US (en_US.UTF-8); UI: en-US Flatpak Calc: threaded
Created attachment 192299 [details] Example file showing the incorrect behavior An example file with the model
I can confirm the issue. When using lpsolve (LibreOffice Linear Solver) I get a message saying that the model is infeasible (which is expected). However, with CoinMP I get a solution to the model: X1 = 26666650000 X2 -13333324997 Z = 13333325003 Tested with Version: 24.8.0.0.alpha0+ (X86_64) / LibreOffice Community Build ID: 379968864c42f4bd99d874a4ce1949dd6eed45b8 CPU threads: 16; OS: Linux 6.5; UI render: default; VCL: kf5 (cairo+xcb) Locale: pt-BR (pt_BR.UTF-8); UI: en-US Calc: CL threaded
I just got the 24.02 update and tested it again. I now also get X1 = 26666650000 X2 -13333324997 Z = 13333325003 Version: 24.2.0.3 (X86_64) / LibreOffice Community Build ID: da48488a73ddd66ea24cf16bbc4f7b9c08e9bea1 CPU threads: 8; OS: Linux 6.6; UI render: default; VCL: gtk3 Locale: en-US (en_US.UTF-8); UI: en-US Flatpak Calc: threaded
Dear Patrick Jansky, 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