GLPK Version Specific Notes

When building PyGLPK, certain functions will be disabled depending on what version of GLPK the build process believes it is using. Below is a list of GLPK versions, and descriptions of what functionality will not work in earlier versions. (Or, in some cases, later versions.)

The examples may use a hypothetical glpk.LPX instance named lp for illustrative purposes.

GLPK 4.39

• The interior point solver often does not detect infeasibility on infeasible problems.

GLPK 4.38

• The interior point solver often crashes on infeasible problems.

GLPK 4.37 and higher

• On OS X, the build of the shared library is broken for all versions after and including GLPK 4.37.

GLPK 4.33

• This release had a bug in the integer-solver routines that make parameters cause GLPK to crash. This was fixed in subsequent versions.

GLPK 4.31

• Addition of a LPX.DUAL constant for the meth keyword parameter of the LPX.simplex solver method.
• Addition of the LPX.SF_GM, LPX.SF_EQ, LPX.SF_2N, LPX.SF_SKIP, and LPX.SF_AUTO constants, for the LPX.scale method’s argument.

GLPK 4.23

• Addition of the gmi_cuts keyword parameter for the LPX.integer solver.

GLPK 4.23

• Addition of the mir_cuts keyword parameter for the LPX.integer solver.

GLPK 4.21

• The ability of the LPX.integer callback to have select, prepro, and branch methods called by the callback procedure. For the same reasons, the Tree methods select, can_branch, and branch_upon do not appear until this version.
• Addition of the pp_tech keyword parameter for the LPX.integer solver, and associated constants.

GLPK 4.20

• The keyword parameters of the LPX.integer MIP solver method including callbacks, and associated constants for the many keyword parameters, as well as all types associated therein, most notably Tree and TreeNode.

GLPK 4.19

• The Environment.mem_limit attribute for setting the maximum number of megabytes the GLPK will allocate.