This is a short post on the cut selection mechanism in the mixed-integer optimization solver SCIP and things I used for its implementation in the SCIP.jl Julia wrapper. You can check out the corresponding pull request for completeness.
Table of Contents Callbacks? SCIP plugins Cut selection Cut selector interface Some C-Julia magic Callbacks? The space of mixed-integer optimization solvers is mostly divided between commercial, closed-source solvers and academic solvers open in source code.
Today was the release of SCIP.jl v0.11, the first release switching to SCIP 8. The major change in this (massive) release was the rewrite of the nonlinear optimization part, using a so-called expression framework. The rewrite of the wrapper had some fairly tedious parts, debugging C shared libraries is quickly a mess with cryptic error messages. But the nonlinear rewrite gave me the opportunity to tweak the way Julia expressions are passed to SCIP in a minor way.