JuMP 0.21 is released

We are happy to announce the release of JuMP 0.21! Since the 0.20 release, 32 pull requests have been merged and 34 issues closed (listed here). The release is packed with new features and contains a couple of breaking changes. We’ll give only a quick summary of the changes here. See the release notes for more details. Here’s an incomplete list of new features:

The most visible breaking change stems from a refactoring of how we handle solver parameters. They are now treated more transparently through MathOptInterface’s optimizer attribute mechanism rather than being passed as constructor keyword arguments. The effect of this is that with_optimizer has been replaced by optimizer_with_attributes and set_optimizer_attribute. Follow the examples in the deprecation warnings as a guide to update existing code.

This release knocks out a number of major items on our roadmap for JuMP 1.0. Stay tuned for more progress!