We are happy to announce that OpenSolver 2.6 has been released.
This is a major release that supports Office 2011 for Mac OSX for the first time! Nearly all of the features of the Windows version are working on Mac, the only notable exception is the non-linear NOMAD solver, which is not supported on the Mac version at this stage. However, all of the other non-linear solvers are available as normal.
This brings us to the other main addition in this release which is the ability to use the COIN-OR non-linear solvers locally. The Bonmin and Couenne solvers were previously only available on NEOS as cloud-based solvers, but they can now be used on your machine locally (both Windows and Mac), which should offer more convenience. This feature is very experimental, as these solvers rely on us converting the Excel model into another model format and we currently only support doing this for a subset of the functions in Excel (most common functions are working). These solvers will fail if your spreadsheet uses functions OpenSolver cannot interpret. If you get a message about an unsupported function, please let us know so we can look at adding it in. These solvers are included in the ‘Advanced’ release, more on that next.
The last main difference in this release is the release format. Instead of offering a single download, we are offering separate downloads for Windows and Mac. This is so Windows users don’t have to download the solvers for Mac, and vice-versa. We are also introducing ‘Linear’ and ‘Advanced’ downloads. The Linear download only contains the linear CBC solver, whereas the experimental Advanced download comes with the non-linear solvers Bonmin, Couenne, and NOMAD. Both releases can use the NEOS solvers, and can use Gurobi if installed on the machine. If you aren’t sure, the default download is the Linear version for your computer (either Windows or Mac as appropriate).
Other changes include:
- NEOS solvers now write AMPL files to disk before sending the model to NEOS. These can be used to run the model locally using AMPL if you have it installed
- Resolve bugs introduced by system-locale settings
- Upgrade NOMAD to v3.6.2
- Bugfixes for non-linear NOMAD solver
- Bugfixes for NEOS solvers
- Various other bugfixes
You can see the releases here. There are a lot of changes in this release, especially since it is the first Mac release, and we are looking for any feedback you have, as well as any problems you might run into while using it.