Xpress Update 8.10.6

Community Manager

4 years ago

Xpress Update 8.10.6 is now available for Window, Linux, MacOS and Solaris on x86-64,

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This is the latest update for the Xpress 8.10 release branch. Please note that the Windows, Linux or Solaris archives must be extracted over a prior installation of FICO Xpress 8.10. This update requires an Xpress 8.10 license.

Release Notes:

Xpress Optimizer 36.01.16

Fixed an issue in presolve that could introduce small constraint violations.
XPRSfixglobals without rounding should no longer impose a lower bound greater than the semi-continuous lower bound for semi-continuous variables.
Fixed an issue with querying 64bit integer attributes/controls in matlab.
Fixed a performance issue in the GCD detection of continuous columns.
Fixed a bug in the LP reader which could lead to files with fixed columns not being read.
Fixed an issue in big-M presolving that could cause incorrect matrix coefficients.
Fixed an issue in which an SLP license was required to solve a PWL problem.
Fixed an issue that could prevent heuristics from finding solutions in presence of very small matrix coefficients.
Fixed an issue where the "No IP reductions" flag of PRESOLVEOPS would not be respected.
Fixed an issue with the interaction of dual reductions and variable eliminations.
Fixed an issue with presolve eliminations on problems with very small coefficients that could lead to numerical instability.
Fixed an issue with general integer variables bounded away from zero appearing in SOS constraints that could lead to wrong results.
Fixed a potential memory leak in MIQCPs.
Fixed a problem where an incorrect message about non-convexity could be printed for a quadratic problem instead of an out-of-memory.
Fixed an uninitialized memory read in presolve
Fixed an issue with piecewise-linear constraints when presolve was off and the first/last breakpoint was inside the bound interval of the input variable which could lead to incorrect results.
Fixed an issue with convex/concave piecewise-linear functions in combination with other pieciewise-linear functions with fixed outcome that could lead to incorrect results.
Fixed an issue in the integer presolver related to protected rows.
Fixed an issue in user interruption through a non-zero return code from the barlog callback.
[Python] Fixed the single-line problem definition in the Python interface where the maximization sense was not read.
[Python] Errors that occur in Python callback functions are raised when the solve terminates.
[Python] Fixed a reference counting error when copying NumPy arrays containing Xpress objects.
[Python] Fixed an issue where data passed to the getgencons and getpwlcons Python functions was not correctly passed to the Optimizer.
[Python] Fixed an incorrect construction of the quotient of a function to a variable in the Python interface.
[Python] Fixed a problem where the Python module could hang when solving many problems simultaneously.
[Python] Fixed a problem where the Xpress module would fail to load in certain versions of Python on macOS due to hardened runtime settings.
[Python] Fixed an issue that occasionally caused Python to crash on exit.

Xpress Nonlinear 36.01.16

Fixed a problem that could cause a crash in Knitro.
Fixed a potential memory corruption in XSLPgetslpsol.
Fixed a potential memory corruption when computing the Hessian of min/max operators.
Fixed an issues where empty rows and columns were dropped and not correctly postsolved when presolve was off in case XSLP_PRESOLVELEVEL was full.
Fixed an issue where having 35 or more distinct user functions could lead to an error about piecewise-linear functions.
Fixed a potential crash in the .nl reader.
Fixed a potential crash in the formula parser.
Fixed an issue where some information from the previous solve was lost when calling XSLPmaxim with the c/continue flag.
Fixed an issue where solutions might have incorrectly been rejected due to an incorrect objective computed from an objective transfer row.
Fixed an issue where the KEEPBEST bit of XSLP_FILTER was not correctly obeyed.
Fixed an issue in postsolve that could lead to failures.