下面是使用装饰器语法的简单Pyomo脚本-我想了解如何在类内使用此语法-在这种情况下,在Model
内部。
无类版本
from pyomo.environ import *
import random
random.seed(1000)
model = AbstractModel()
model.N = Param(within=PositiveIntegers)
model.P = Param(within=RangeSet(1, model.N))
model.M = Param(within=PositiveIntegers)
model.Locations = RangeSet(1, model.N)
model.Customers = RangeSet(1, model.M)
model.d = Param(
model.Locations,
model.Customers,
initialize=lambda n, m, model: random.uniform(1.0, 2.0),
within=Reals,
)
model.x = Var(model.Locations, model.Customers, bounds=(0.0, 1.0))
model.y = Var(model.Locations, within=Binary)
@model.Objective()
def obj(model):
return sum(
model.d[n, m] * model.x[n, m] for n in model.Locations for m in model.Customers
)
@model.Constraint(model.Customers)
def single_x(model, m):
return (sum(model.x[n, m] for n in model.Locations), 1.0)
@model.Constraint(model.Locations, model.Customers)
def bound_y(model, n, m):
return model.x[n, m] - model.y[n] <= 0.0
@model.Constraint()
def num_facilities(model):
return sum(model.y[n] for n in model.Locations) == model.P
无法使用的类中的装饰器版本:
from pyomo.environ import *
import random
random.seed(1000)
class Model:
def __init__(self):
self.model = AbstractModel()
self.model.N = Param(within=PositiveIntegers)
self.model.P = Param(within=RangeSet(1, self.model.N))
self.model.M = Param(within=PositiveIntegers)
self.model.Locations = RangeSet(1, self.model.N)
self.model.Customers = RangeSet(1, self.model.M)
self.model.d = Param(
self.model.Locations,
self.model.Customers,
initialize=lambda n, m, model: random.uniform(1.0, 2.0),
within=Reals,
)
self.model.x = Var(
self.model.Locations, self.model.Customers, bounds=(0.0, 1.0)
)
self.model.y = Var(self.model.Locations, within=Binary)
@model.Objective()
def obj(model):
return sum(
model.d[n, m] * model.x[n, m]
for n in model.Locations
for m in model.Customers
)
@model.Constraint(model.Customers)
def single_x(model, m):
return (sum(model.x[n, m] for n in model.Locations), 1.0)
@model.Constraint(model.Locations, model.Customers)
def bound_y(model, n, m):
return model.x[n, m] - model.y[n] <= 0.0
@model.Constraint()
def num_facilities(model):
return sum(model.y[n] for n in model.Locations) == model.P
我无能为力,只有几个问题:
__init__
方法中的函数吗?我想我首先缺少的是使用类的好处。如果您只是想以某种方式包装模型构造,那么更好的方法是使用函数:
def create_model(): model = AbstractModel() ... @model.Constraint() def some_rule_function(model): ... ... return model
然后您可以让您的课程
Model
刚刚在构造中收到抽象模型:
class Model: def __init__(self, model): self.model = model # other behavior you want to add to the class
示例用法:
model = Model(create_model())