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