COPT¶

Initial setup¶

from pyoptinterface import copt

model = copt.Model()

You need to follow the instructions in Getting Started to set up the optimizer correctly.

If you want to manage the license of COPT manually, you can create a copt.Env object and pass it to the constructor of the copt.Model object, otherwise we will initialize an implicit global copt.Env object automatically and use it.

env = copt.Env()

model = copt.Model(env)

The capability of `copt.Model`¶

Supported constraints¶

Constraint	Supported
`model.add_linear_constraint`	✅
`model.add_quadratic_constraint`	✅
`model.add_second_order_cone_constraint`	✅
`model.add_exp_cone_constraint`	✅
`model.add_sos_constraint`	✅

Supported model attribute ¶

Attribute	Get	Set
Name	❌	❌
ObjectiveSense	✅	✅
DualStatus	✅	❌
PrimalStatus	✅	❌
RawStatusString	✅	❌
TerminationStatus	✅	❌
BarrierIterations	✅	❌
DualObjectiveValue	✅	❌
NodeCount	✅	❌
NumberOfThreads	✅	✅
ObjectiveBound	✅	❌
ObjectiveValue	✅	❌
RelativeGap	✅	✅
Silent	✅	✅
SimplexIterations	✅	❌
SolverName	✅	❌
SolverVersion	✅	❌
SolveTimeSec	✅	❌
TimeLimitSec	✅	✅

Supported variable attribute ¶

Attribute	Get	Set
Value	✅	❌
LowerBound	✅	✅
UpperBound	✅	✅
Domain	✅	✅
PrimalStart	✅	✅
Name	✅	✅

Supported constraint attribute ¶

Attribute	Get	Set
Name	✅	✅
Primal	✅	❌
Dual	✅	❌

Solver-specific operations¶

Parameter¶

For solver-specific parameters, we provide get_raw_parameter and set_raw_parameter methods to get and set the parameters.

model = copt.Model()

# get the value of the parameter
value = model.get_raw_parameter("TimeLimit")

# set the value of the parameter
model.set_raw_parameter("TimeLimit", 10.0)

Attribute¶

COPT supports attribute for the model. We provide model.get_raw_attribute(name:str) to get the value of attribute.

Information¶

COPT provides information for the model components. We provide methods to access the value of information.

Information of variable: model.get_variable_info(variable, name: str)
Information of constraint: model.get_constraint_info(constraint, name: str)

We also provide copt.COPT to contain all the constants in coptpy.COPT.

For number of variables (columns) in the problem:

cols = model.get_raw_attribute(copt.COPT.Attr.Cols)

For reduced cost of a variable:

rc = model.get_variable_info(variable, copt.COPT.Info.RedCost)

For upper bound of a constraint:

ub = model.get_constraint_info(constraint, copt.COPT.Info.UB)