HiGHS

class pyomo.contrib.appsi.solvers.highs.HighsResults(solver)

Bases: Results

class pyomo.contrib.appsi.solvers.highs.Highs(only_child_vars=True)

Bases: PersistentBase, PersistentSolver

Interface to HiGHS

class Availability(value)

Bases: IntEnum

An enumeration.

BadLicense = -2

BadVersion = -1

FullLicense = 1

LimitedLicense = 2

NeedsCompiledExtension = -3

NotFound = 0

add_block(block)

add_constraints(cons: List[_GeneralConstraintData])

add_params(params: List[_ParamData])

add_sos_constraints(cons: List[_SOSConstraintData])

add_variables(variables: List[_GeneralVarData])

available()

Test if the solver is available on this system.

Nominally, this will return True if the solver interface is valid and can be used to solve problems and False if it cannot.

Note that for licensed solvers there are a number of “levels” of available: depending on the license, the solver may be available with limitations on problem size or runtime (e.g., ‘demo’ vs. ‘community’ vs. ‘full’). In these cases, the solver may return a subclass of enum.IntEnum, with members that resolve to True if the solver is available (possibly with limitations). The Enum may also have multiple members that all resolve to False indicating the reason why the interface is not available (not found, bad license, unsupported version, etc).

Returns:available – An enum that indicates “how available” the solver is. Note that the enum can be cast to bool, which will be True if the solver is runable at all and False otherwise. Return type:Solver.Availability

property config: HighsConfig

An object for configuring solve options.

Returns:An object for configuring pyomo solve options such as the time limit. These options are mostly independent of the solver. Return type:SolverConfig

get_duals(cons_to_load=None)

Declare sign convention in docstring here.

Parameters:cons_to_load (list) – A list of the constraints whose duals should be loaded. If cons_to_load is None, then the duals for all constraints will be loaded. Returns:duals – Maps constraints to dual values Return type:dict

get_primals(vars_to_load=None, solution_number=0)

get_reduced_costs(vars_to_load=None)

Parameters:vars_to_load (list) – A list of the variables whose reduced cost should be loaded. If vars_to_load is None, then all reduced costs will be loaded. Returns:reduced_costs – Maps variable to reduced cost Return type:ComponentMap

get_slacks(cons_to_load=None)

Parameters:cons_to_load (list) – A list of the constraints whose slacks should be loaded. If cons_to_load is None, then the slacks for all constraints will be loaded. Returns:slacks – Maps constraints to slack values Return type:dict

property highs_options

returns: highs_options – A dictionary mapping solver options to values for those options. These

are solver specific.

Return type:dict

is_persistent()

Returns:is_persistent – True if the solver is a persistent solver. Return type:bool

load_vars(vars_to_load=None)

Load the solution of the primal variables into the value attribut of the variables.

Parameters:vars_to_load (list) – A list of the variables whose solution should be loaded. If vars_to_load is None, then the solution to all primal variables will be loaded.

remove_block(block)

remove_constraints(cons: List[_GeneralConstraintData])

remove_params(params: List[_ParamData])

remove_sos_constraints(cons: List[_SOSConstraintData])

remove_variables(variables: List[_GeneralVarData])

set_instance(model)

set_objective(obj: _GeneralObjectiveData)

solve(model, timer: Optional[HierarchicalTimer] = None) → Results

Solve a Pyomo model.

Parameters:

• model (_BlockData) – The Pyomo model to be solved
• timer (HierarchicalTimer) – An option timer for reporting timing

Returns:

results – A results object

Return type:

Results

property symbol_map

update(timer: Optional[HierarchicalTimer] = None)

property update_config

update_params()

update_variables(variables: List[_GeneralVarData])

version()

Returns:version – A tuple representing the version Return type:tuple