Xpress update release 8.0.10

Document created by zsoltcsizmadia@fico.com on Jul 21, 2017
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Xpress update 8.0.10 is now available on Box.com for Windows, Linux and Mac from

 

https://fico.box.com/v/xpress-8-0-10

 

Xpress-Optimizer 29.01.16 release notes:

 

* Fixed a bound reduction bug affecting (MI)QCQPs.

* Fixed a problem with nondefault setting REFINEOPS=-1 causing a crash during the MIP search.

* Fixed an issue with bound reduction in problems with linear and quadratic terms that may erroneously claim the problem to be infeasible when feasible and viceversa.

* Fixed an issue with the rounding heuristics that could result in a violated partial integer solution.

* Fixed an issue with MIP cutoff tightening that could result in valid solutions being dropped.

* Added missing checks against time limit to the local search heuristics.

* Changing the objective sense (explicitly with XPRSchgobjsense or implicitly by calling XPRSminim/XPRSmaxim) should no longer cause pre-loaded MIP solutions to be dropped.

* Fixed an issue in the connected component presolver for problems with very large objective values that in rare cases could result in the problem being declared infeasible.

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

* Fixed an issue with re-presolving of MIPs containing both indicator constraints and quadratic constraints.

* Fixed an issue in presolving which could lead to infeasible solutions declared to be feasible.

* Fixed an issue where the Optimizer crashed in case indicators are present.

* Fixed the creation of constraints in Python by means of their components (body, rhs, sense).

* Fixed the addition of non-continuous columns on a pre-existing problem in Python.

* Fixed the printing of a problem's attributes and controls in the Python interface.

* Fixed an issue with the use of NumPy 32bit integers and floats in the Python interface.

* Fixed an issue with the product of expressions in the Python interface.

* Fixed an issue in error reporting with the Python interface.

* Fixed a bug in the representation of quadratic expressions in the Python interface.

* Fixed a bug in the construction of linear and quadratic expressions in Python.

* Added support for NumPy int64 and float64 arrays in Python.

* Added support for broadcast operations between expressions/variables and NumPy vectors and scalars.

* Fixed an issue in the Python interface that might use and require arrays of row/column indices of incorrect size.

* Fixed an issue in the Python interface that occurs when doing NumPy operations on non-expression objects.

* Fixed an issue in the Python interface that might trigger a crash when multiple calls are made to the same API function.

* Fixed an issue in the Python interface that returns an error when adding an empty list of constraints or variables.

 

Xpress-Nonlinear 29.01.16 release notes:

 

* Fixed an incorrect bound reduction in expressions with arctan() operators.

* Fixed an issue that might prevent SLP from handling formulae within bound tightening.

* Fixed an incorrect bound reduction in constraints with nonlinear and quadratic parts with at least one off-diagonal term.

* Fixed a problem where the setting XSLP_MATRIXTOL was ignored.

* Fixed a convergence issue related to variables appearing in neutral rows.

* Fixed a problem which could cause an incorrect objective function to be used in an XSLPunconstruct and XSLPconstruct sequence.

 

This is the latest Xpress update for the Xpress 8.0 release branch. Please note that it must be installed over a prior installation of FICO Xpress 8.0 and requires a valid Xpress 8.0 license.

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