GAMSPy 1.28.0 (2026-09-15)

New features

#880: Add the package wide option STRICT_POWER_OPERATOR which makes ** generate rPower for every exponent, matching the GAMS ** operator exactly.
#889: Add typed symbol accessors to Container: getSet, getAlias, getUniverseAlias, getParameter, getVariable, getEquation, and getSymbol(name, type) which narrows its return type to the requested symbol type.

#878: Internal performance improvements for generateRecords.
#879: Setting records, converting them to and from numpy, and looking up UELs are all faster now, especially for symbols with large domains.
#890: Every GAMSPy exception now derives from the new GamspyBaseException, so a single except clause can handle any GAMSPy failure. GamspyException keeps covering only GAMS execution errors.
#897: Added gamspy install solver --licensed to install every add-on solver permitted by the active license, and gamspy uninstall solver --unlicensed to uninstall installed add-on solvers no longer permitted by it.
#899: Add the package wide option LICENSE_PATH (also settable via the GAMSPY_LICENSE_PATH environment variable) to use a license file without installing it.

#880: Map ** with a fractional exponent (e.g. x ** 2.9998) to rPower instead of power, which used to round it to the nearest integer.
#881: Make SDDP training, simulation, and cut-selection bound evaluation work with the bundled demo license.
#883: Merge the solver configuration of the cuopt release archive into the gamsconfig.yaml of the GAMS system directory instead of overwriting it.
#887: An explicitly passed empty Container is no longer ignored inside a Container context manager and Alias/UniverseAlias redeclarations no longer emit a duplicate declaration.
#890: whereMaxAbs now reports the record with the largest magnitude instead of None when that record holds a negative value.
#893: set_options now raises ValidationError for an unrecognized option name instead of silently accepting it.
#900: Model.freeze now raises a ValidationError if a variable of the model ends with the reserved _var suffix instead of letting GAMS fix that variable to zero, and a failed freeze no longer leaves the model in a frozen state.

#890: Add examples in the docstrings of find*, count*, where*, and shape functions.
#902: Fix swapped left and right gradients in the piecewise linear functions example.

#886: Refactor test suite to decrease duplication.
#892: Type check the formulations modules with ty instead of excluding them.