Forum Discussion
Implementing the TSP with DFJ subtour elimination constraints
To learn how callbacks work in Xpress, based on the answer by Daniel Junglas in this question: https://community.fico.com/s/question/0D54W00008P73MsSAJ/lazy-cut-callback-in-java, I've been experiment...
I confirm, syncing with XPRS_SOL is not correct as this will only sync LP information. With only this the values returned by XPRBvar.getSol() will be fetched via XPRSgetlpsol, which is not the right thing after optimization completes. Syncing with XPRS_SOL_MIP instead sets up the problem so that solution values are fetched via XPRSgetmipsol.