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!