| Summary: | Linear solver says 'model is infeasible', when real problem is non-linearity | ||
|---|---|---|---|
| Product: | LibreOffice | Reporter: | Jan Egil Kristiansen <styrheim> |
| Component: | Calc | Assignee: | Not Assigned <libreoffice-bugs> |
| Status: | NEW --- | ||
| Severity: | trivial | CC: | aron.budea, serval2412 |
| Priority: | low | ||
| Version: | Inherited From OOo | ||
| Hardware: | All | ||
| OS: | All | ||
| Whiteboard: | |||
| Crash report or crash signature: | Regression By: | ||
| Bug Depends on: | |||
| Bug Blocks: | 113360 | ||
| Attachments: |
Simple but non-linear optimization problem.
Solver status message |
||
Confirmed. According to specification [1], this text comes from the solver engine, the appropriate one in this case would be "The model is not linear." [1] https://www.openoffice.org/specs/calc/features/Solver.odt ** Please read this message in its entirety before responding ** 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 on a currently supported version of LibreOffice (5.4.1 or 5.3.6 https://www.libreoffice.org/download/ If the bug is present, please leave a comment that includes the version of LibreOffice and your operating system, and any changes you see in the bug behavior If the bug is NOT present, please set the bug's Status field to RESOLVED-WORKSFORME and leave a short comment that includes your version of LibreOffice and Operating System 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) http://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: http://webchat.freenode.net/?channels=libreoffice-qa Thank you for helping us make LibreOffice even better for everyone! Warm Regards, QA Team MassPing-UntouchedBug-20170901 Created attachment 137214 [details]
Solver status message
I tried the attachment and got following status message:
"Process stopped at iteration 338 if 2000.
Process stopped due to stagnation."
On pc Debian x86-64 with master sources updated today, I don't reproduce this. I got the same result as Thomas, except the number of iterations is slightly different. Thomas, Julien, did you open Options... in the Solver dialog, and switch to LibreOffice (or LibreOfficeDev) Linear Solver? (In reply to Aron Budea from comment #5) > Thomas, Julien, did you open Options... in the Solver dialog, and switch to > LibreOffice (or LibreOfficeDev) Linear Solver? Thank you Aron, I could reproduce the pb. It seems "infeasible" may have different reasons (see http://lpsolve.sourceforge.net/5.5/). CoinMP also uses this expression. I am not sure that linear solvers are capable to detect non-linearity. That is why I do not think that error messages should be changed. Dear Jan Egil Kristiansen, 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://kiwiirc.com/nextclient/irc.freenode.net/#libreoffice-qa Thank you for helping us make LibreOffice even better for everyone! Warm Regards, QA Team MassPing-UntouchedBug Dear Jan Egil Kristiansen, 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 Bug still here as of 7.4.6.2 As I get older and wiser, I think it may be unreasonable to expect a linear solver to detect nonlinearity in the model. Maybe the error message should just hint that nonlinearity might be the problem? |
Created attachment 126062 [details] Simple but non-linear optimization problem. Optimizing a model with the linear solver, but the variables are multiplied with each other, making the model non-linear. Error message says 'model is infeasible', I think it should rather say that 'model is non-linear'. (When staring at a feasible solution, the 'infeasible' message is rather confusing.)