OpenSolver for Google Sheets 2.3.1

Hello everyone,

We are pleased to announce a new release of OpenSolver for Google Sheets. This fixes bugs in the GLPK solver and NEOS-Cbc solver options which made them unavailable. These engines should now be working and available.

Errors which stopped the GLPK solver from running were related to local variables in scriptlets not being defined before Html template objects ‘glpkWorkerJs’ and ‘glpkRunnerJs’ were evaluated and ran these scriptlets. Errors such as “ReferenceError: gmplModel not defined” should now go away since local copies of these variables are initialised inside these scriptlets.

As of January 8, 2021, NEOS requires that an email address be submitted with every job. The NEOS-Cbc bug was related to this – originally we did not include a user email address in the xml file sent to the NEOS server.

Since NEOS now requires that each job contain an email address, we include the user’s email address in the xml file. This email address is only sent to NEOS when the model is being solved and only if the user selects NEOS-Cbc as the solver engine.

We have updated our privacy policy and information about OpenSolver for Google Sheets to reflect these changes.

As always, we welcome your feedback. Please comment below if it works ok, or if you encounter issues, or if you have any questions regarding the new release. Thanks!

OpenSolver 2.9.4 Beta Release

Hello everyone,

We’ve released OpenSolver 2.9.4 for beta testing! You can download this new version of OpenSolver from: https://sourceforge.net/projects/opensolver/files/.

Below are the release notes that cover the changes made in this new version of OpenSolver:

V2.9.4 – 2021-01-15

  • Extended support for special characters in sheet names
  • Removed support for Satalia Solver Engine since Satalia no longer offers an online service
  • Added fix for NEOS email validation
  • Added support for value-seeking models with no constraints

V2.9.3 – 2020-03-01

  • Added support for using Gurobi 9.0
  • Added a temp fix for running consecutive operations on Excel64bit

As always, we welcome your feedback. Please comment below if it works ok, or if you encounter issues, or if you have any questions regarding the new release. Thanks!

OpenSolver for Google Sheets working for new users

Hello everyone,

We have implemented a fix so that OpenSolver for Google Sheets should now be accessible and working again.

It seems that some of the comments in our code were causing an OAuth scope /auth/script.scriptapps – which we do not need or use – to be detected. These comments have now been removed, so we expect error messages like “Sign-in with Google temporarily disabled for this app” to stop appearing.

We’d greatly appreciate it if you could test that it now works. Please comment below if OpenSolver for Google Sheets works for you, or if you encounter any issues, or if you have any other questions.

OpenSolver 2.9.3 Beta Release

Hi everyone,

We have now released OpenSolver 2.9.3 for beta testing! You can download this new version of OpenSolver on https://sourceforge.net/projects/opensolver/files/. Below are the release notes that cover the changes made in this new version of OpenSolver:

v2.9.3 – 2020/03/02

  • Added support for using Gurobi 9.0
  • Added a temp fix for running consecutive operations on Excel64bit

v2.9.2 – 2019-02-04

  • Add support for NEOS CPLEX as a new solver.
  • Add import LP file feature.
  • Add Examples files and submenu.
  • Fix memory error when solving consecutive non-linear models in 64bit.

As always, we welcome any feedback! Please comment below if it works ok, or if there are any issues encountered, or if you have any questions regarding the new release. Thanks!

OpenSolver 2.8.6 (6 Mar 2017)

We have released OpenSolver version 2.8.6 which fixes various bugs:

  • We have updated the URL for NEOS so these solvers will work again
  • Made changes to support Gurobi v7
  • Set worksheet calculation in the OpenSolver file to automatic to avoid setting it to manual for the entire Excel session when OpenSolver is loaded. Thanks to the users that reported this issue.
  • Other minor bugfixes

You can get the new version here.

As always, please let us know about any issues you might have, or features you would like to see in future releases!

OpenSolver 2.8.5 (3 Nov 2016)

Today we are releasing OpenSolver version 2.8.5 which fixes a bug brought about by the October update to Excel 2016. This bug in Excel prevented clicks on the constraint section of the model creation form in OpenSolver, and there is a workaround in today’s update so that things work as intended.

You can get the new version here.

The release also includes a new feature that a number of users have asked for in the past, which is the ability to use the NOMAD solver to optimize models where the objective and constraints depend on the output of macros. For instance, one user wanted to use the results of a Pivot Table that depended on the variable values in their model, but Pivot Tables are not updated when the sheet is recalculated so this did not previously work with OpenSolver. Another example comes from Judd Larson at the University of Wyoming. Judd’s problem involved optimizing a function that depended on the solution to a series of differential equations, which he was solving using his VBA implementation of an ODE solver. This is not a problem that can be expressed and solved in the traditional way that OpenSolver supports, but is possible to solve now with the new ability to incorporate the macro into the solution process. We are very pleased to offer a solution to a tough problem like this! For more information on how this feature works, please see the new section in the documentation describing this feature.

As always, please let us know about any issues you might have, or features you would like to see in future releases!

OpenSolver 2.8.4 (12 Oct 2016)

We have just released OpenSolver 2.8.4 which fixes a bug in the 2.8.3 release that caused it to crash on the newest versions of Excel (in most cases the Office 365 versions). This release also fixes a bug where the saved solver choice could get corrupted and force you to re-select the solver.

You can download the 2.8.4 release here.

Don’t forget to enable the update checker in OpenSolver if you want to be notified automatically of new updates like this one.

As always, please let us know if you have any feedback or problems.

OpenSolver 2.8.3 (05 Oct 2016)

We are happy today to announce the release of OpenSolver 2.8.3! This is a bugfix release for the 2.8.2 release, but we are also using the occasion to mark the 2.8.x releases as stable. This means 2.8.3 will become the default download for all users and is the recommended version for everyone.

You can download OpenSolver 2.8.3 here.

This update is primarily a bugfix release (the changelog lists around 20 significant fixes) as well as two new features.

The first new feature is extended support for using the solution on the sheet as the starting point for the solver. Passing the solution as a “warm start” to the solver in this way is now supported by all solvers except CBC. This functionality is enabled automatically – if the initial solution on the sheet is feasible, it will be sent to the solver. This can give significant reductions in solve time when solving tough integer problems.

The other big change in this release is our first partial support for Excel 2016 for Mac. This version should work if your version of Excel is at least 15.28. Unfortunately, the VBA support on this version of Excel is very limited, and so it has been very difficult to get OpenSolver working. We do not yet have the full range of functionality running, but we do have some core features working for those that need to use Excel 2016 for Mac or want to help with testing. Right now, the features that we know are working are model creation and manipulation, and solving using the linear solvers (CBC and Gurobi).

There are some major changes in the way Excel 2016 for Mac works that have made our life difficult. The most important of these is that Excel is now sandboxed for security reasons, which makes it harder for us to run the optimization solvers. Currently, the only workaround we have come up with requires you to run an installer after you download OpenSolver that installs the solvers we use on your system so that they can be used by Excel. Unfortunately this means that you will need administrative privileges on your computer to set up OpenSolver if you want to use Excel 2016 on Mac. Please see the installation page for more information about this.

It seems that Excel 2016 for Mac is significantly slower than any other Excel release, which leads to much slower OpenSolver solve times. We can only hope that Microsoft improve its speed in future releases.

We appreciate any feedback you might have on the release, especially in regards to Excel 2016 for Mac. If you do encounter any problems, please either use the “Report Issue” button from inside OpenSolver, or leave a comment here so that we can address the problem.

OpenSolver 2.8.2 Pre-release

We have just uploaded OpenSolver 2.8.2, available on our SourceForge site here.

This is a second attempt to work around the “Automation Error” bug that some users are seeing on some versions of Excel. (This appears to be caused by a VBA bug that is corrupting the cached code. We have now “cleaned” the code)

As always, please send us any feedback and let us know if you have any problems.

OpenSolver 2.8.1 Pre-release

We have just uploaded OpenSolver 2.8.1, available here.

This fixes two bugs with the 2.8.0 release. Some users may have encountered an “Automation Error” depending on their version of Excel, which we have now fixed. Additionally we have fixed an error that occurred when cancelling the “Set QuickSolve Parameters” dialog.

As always, please send us any feedback and let us know if you have any problems.

OpenSolver 2.8.0 Pre-release

We are happy today to announce the release of OpenSolver 2.8.0!

We will be releasing this first as a pre-release for wider testing before releasing it as stable in the near future. Anybody that has elected to receive update checks for experimental updates should get an update notification in the next day, otherwise the notification will come later once it is tested further (if you enabled the update checker).

You can download OpenSolver 2.8.0 Prerelease here.

This update contains a large number of bugfixes (the changelog lists over 30 major fixes!) as well as some new features. It fixes a lot of problems that users encountered in version 2.7.1. In particular, it fixes the compile error message “Method or data member not found” that some Mac users were encountering due to VBA becoming case-sensitive and treating Me.width and Me.Width differently. If you somehow still run into this message on the latest version, please let us know immediately so we can work with you to fix it.

There are a couple of changes to the way models are defined. First of all, it is now possible to define ranges in the objective, variables and constraint cells that are not on the same sheet as the model. Beforehand this was not consistently allowed, but now there should be no problems. NOTE: For the non-linear solvers Bonmin and Couenne that use our formula parser, the entire model needs to be on the same sheet due to limitations in the formula parser. This is something we want to fix as soon as possible.

The other big change to the way models are defined is that models can now be defined using named ranges. Now you can give names to ranges on the sheet and use these names when defining the model. For instance, if you have a named range “production” in A1:A4 and another named range “capacity” in B1:B4, instead of entering the constraint as “A1:A4 <= B1:B4”, you can now add it as “production <= capacity”. If the named range is changed to point to a different set of cells, the model will update and use the new set of cells when solving the problem. This change will allow for much more expressive power when creating models, and makes it easier to keep track of what each constraint means when defining the model.

We have also revamped the way we show the solver output when “Show optimisation progress while solving” is enabled. Previously we used a command prompt/terminal window to show the output from the solver, but now we do this inside Excel, along with an easy “Cancel” button to abort the solve. This is a much more stable way of doing things than before, and looks a lot nicer too!

The “About OpenSolver” form now indicates whether OpenSolver has been correctly installed, by which we mean all the files have been unzipped to the same place. If you are having trouble getting any solver to run, please make sure that this form says everything is correctly installed.

Finally, there are some minor changes to the API. We have removed the “GetObjectiveCellWithValidation” method, and have changed “GetObjectiveFunctionCell” to validate by default. A large number of the API methods have been altered to validate their inputs and outputs by default, which can be turned off. We have also added a host of new functions to go along with the ability to define the model using named ranges, which requires working with string arguments rather than ranges.

We appreciate any feedback you might have on the release, including the new features and any future features you might like. If you do encounter any problems, please either use the “Report Issue” button from inside OpenSolver, or leave a comment here so that we can address the problem.

OpenSolver 2.7.1 (28 June 2015)

We have just released OpenSolver 2.7.1 which fixes a number of bugs in the 2.7.0 release. Please upgrade to this version if you are using 2.7.0 (or enable the update checker in OpenSolver to get automatically notified of these changes!).

Note: Unlike earlier versions of OpenSolver, we now correctly pass to the solvers (including CBC) the “Maximum number of iterations” value in the Options dialog. Be sure to set this (and the time limit) to a large value if want to find optimal solutions.

OpenSolver 2.6.1 (15 Feb 2015)

We are pleased to announce the release of OpenSolver 2.6.1. This release contains numerous bugfixes, as well as some new features:

  • Bonmin, Couenne and Gurobi support options set in OpenSolver (e.g. time limit, tolerance)
  • Gurobi now supports extra parameters just as CBC does (see http://opensolver.org/using-opensolver/#gurobi-params)
  • Support for more formulae in the non-linear solvers. SUMIF is now supported.
  • We have updated the COIN-OR solvers included with OpenSolver to CBC 2.9.0, Bonmin 1.8.0 and Couenne 0.5.1
  • The issues with OS X Yosemite have hopefully been resolved

Please let us know how you find it. In particular we are always interested in feedback on the OS X version, which should be a lot more robust now.