pyepo.model.ort

Optimization Model based on Google OR-Tools

Submodules

Classes

`optOrtModel`	This is an abstract class for an OR-Tools pywraplp optimization model
`optOrtCpModel`	This is an abstract class for an OR-Tools CP-SAT optimization model
`shortestPathModel`	This class is an optimization model for the shortest path problem
`shortestPathCpModel`	This class is an optimization model for the shortest path problem using CP-SAT
`knapsackModel`	This class is an optimization model for the knapsack problem
`knapsackModelRel`	This class is relaxed optimization model for knapsack problem.
`knapsackCpModel`	This class is an optimization model for the knapsack problem using CP-SAT

Package Contents

class pyepo.model.ort.optOrtModel(solver='scip')

Bases: pyepo.model.opt.optModel

This is an abstract class for an OR-Tools pywraplp optimization model

_model

OR-Tools linear solver

Type:: pywraplp.Solver

solver

solver backend (e.g. “scip”, “glop”, “cbc”)

Type:: str

solver = 'scip'

_extra_constrs = []

__repr__()

setObj(c)

A method to set the objective function

Parameters:: c (np.ndarray / list) – cost of objective function

solve()

A method to solve the model

Returns:: optimal solution (list) and objective value (float)
Return type:: tuple

copy()

A method to copy the model

Returns:: new copied model
Return type:: optModel

addConstr(coefs, rhs)

A method to add a new constraint

Parameters:

coefs (np.ndarray / list) – coefficients of new constraint
rhs (float) – right-hand side of new constraint

Returns:

new model with the added constraint

Return type:

optModel

class pyepo.model.ort.optOrtCpModel

Bases: pyepo.model.opt.optModel

This is an abstract class for an OR-Tools CP-SAT optimization model

_model

OR-Tools CP-SAT model

Type:: cp_model.CpModel

_OBJ_SCALE = 1000000

_extra_constrs = []

__repr__()

setObj(c)

A method to set the objective function

Parameters:: c (np.ndarray / list) – cost of objective function

solve()

A method to solve the model

Returns:: optimal solution (list) and objective value (float)
Return type:: tuple

copy()

A method to copy the model

Returns:: new copied model
Return type:: optModel

addConstr(coefs, rhs)

A method to add a new constraint

Parameters:

coefs (np.ndarray / list) – coefficients of new constraint
rhs (float) – right-hand side of new constraint

Returns:

new model with the added constraint

Return type:

optModel

relax(): CP-SAT does not support LP relaxation.

class pyepo.model.ort.shortestPathModel(grid, solver='glop')

Bases: pyepo.model.ort.ortmodel.optOrtModel

This class is an optimization model for the shortest path problem

_model

OR-Tools linear solver

Type:: pywraplp.Solver

solver

solver backend

Type:: str

grid

size of grid network

Type:: tuple of int

arcs

list of arcs

Type:: list

grid

arcs = []

_getModel()

A method to build OR-Tools pywraplp model

Returns:: optimization model and variables
Return type:: tuple

class pyepo.model.ort.shortestPathCpModel(grid)

Bases: pyepo.model.ort.ortcpmodel.optOrtCpModel

This class is an optimization model for the shortest path problem using CP-SAT

_model

OR-Tools CP-SAT model

Type:: cp_model.CpModel

grid

size of grid network

Type:: tuple of int

arcs

list of arcs

Type:: list

grid

arcs = []

_getModel()

A method to build OR-Tools CP-SAT model

Returns:: optimization model and variables
Return type:: tuple

class pyepo.model.ort.knapsackModel(weights, capacity, solver='scip')

Bases: pyepo.model.ort.ortmodel.optOrtModel

This class is an optimization model for the knapsack problem

_model

OR-Tools linear solver

Type:: pywraplp.Solver

solver

solver backend

Type:: str

weights

weights of items

Type:: np.ndarray

capacity

total capacity

Type:: np.ndarray

items

list of item index

Type:: list

weights

capacity

items

_getModel()

A method to build OR-Tools pywraplp model

Returns:: optimization model and variables
Return type:: tuple

relax(): A method to get linear relaxation model

class pyepo.model.ort.knapsackModelRel(weights, capacity, solver='scip')

Bases: knapsackModel

This class is relaxed optimization model for knapsack problem.

_getModel()

A method to build OR-Tools pywraplp model (relaxed)

Returns:: optimization model and variables
Return type:: tuple

relax(): A forbidden method to relax MIP model

class pyepo.model.ort.knapsackCpModel(weights, capacity)

Bases: pyepo.model.ort.ortcpmodel.optOrtCpModel

This class is an optimization model for the knapsack problem using CP-SAT

_model

OR-Tools CP-SAT model

Type:: cp_model.CpModel

weights

weights of items

Type:: np.ndarray

capacity

total capacity

Type:: np.ndarray

items

list of item index

Type:: list

weights

capacity

items

_getModel()

A method to build OR-Tools CP-SAT model

Returns:: optimization model and variables
Return type:: tuple