Xpress patch release 8.2.1

Document created by zsoltcsizmadia@fico.com on May 17, 2017
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Xpress patch 8.2.1 is now available on Box for Windows 64 and 32, Linux 64 and Mac 64 from




Xpress-Optimizer 31.01.03 release notes:


* Fixed an issue that could result in a wrong best bound being reported for a MIP solve finishing due to a root re-presolve.

* Fixed a presolving issue which can result in reporting infeasible solution.

* Implied integer variables are less likely to be branched on.

* The optimizer now reports a message when parallel crossover is used.

* Corrected the barrier algorithm to improve solution accuracy for SOCPs in some situations.

* Improved linearization of MIQPs whose quadratic objective contains binary variables only.

* Fixed an issue with re-presolving of MIPs where only indicator constraints remain in the problem.


Xpress-Nonlinear 31.01.03 release notes:


* Improved the behavior of the option to keep the best known iterate as the final solution.

* Improved performance of bound propagation for problems with large linear or quadratic parts.

* New option XSLP_COLINFO_LPVALUE for XSLPgetcolinfo to retrieve the linearized LP optimized solution value of columns.

* Fixed a bug in the creation of the data structure for bound reduction that might trigger incorrect behavior or a crash.


This is the latest Xpress update for the Xpress 8.2 release branch. Please note that it must be installed over a prior installation of FICO Xpress 8.2 and requires a valid Xpress 8.2 license.