Python Pyomo出现错误:检测到常量目标,替换为占位符以防止解算器失败
我正试图用Pyomo解决一个数学规划问题 这是我的密码:Python Pyomo出现错误:检测到常量目标,替换为占位符以防止解算器失败,python,mathematical-optimization,pyomo,Python,Mathematical Optimization,Pyomo,我正试图用Pyomo解决一个数学规划问题 这是我的密码: model = AbstractModel() *####communities* model.I = set() *####suppliers* model.J = set() model.c = Param(model.J) model.p = Param(model.I) model.s = Param(model.J) model.e = Param(model.J) model.b = Para
model = AbstractModel()
*####communities*
model.I = set()
*####suppliers*
model.J = set()
model.c = Param(model.J)
model.p = Param(model.I)
model.s = Param(model.J)
model.e = Param(model.J)
model.b = Param(model.I)
决策变量总共有19*6=114
model.q = Var(model.I,model.J,domain = NonNegativeReals) #bought quantity
目标函数的定义
def obj_expression(model):
return sum(model.c[j]*sum(model.q[i,j] for i in model.I) for j in model.J)
model.OBJ = Objective(rule=obj_expression)
####q11+q12+q13...q1j >= pi
def cons_1(model, i):
return sum(model.q[i,j] for j in model.J) >= model.p[i]
model.vaccine_quantity = Constraint(model.I, rule = cons_1)
疫苗j总量小于供应j
def cons_2(model,j):
return sum(model.q[i,j] for i in model.I) <= model.s[j]
model.supply = Constraint(model.J, rule = cons_2)
我已经复习了好几遍,但我不知道问题出在哪里。
警告是:
param J : c s e :=
"China 1" 10 1000 0.6
"Russian" 10 700 0.92
"UK" 3 2000 0.76
;
WARNING: Constant objective detected, replacing with a placeholder to prevent
solver failure.
WARNING: Empty constraint block written in LP format - solver may error
[ 0.05] Processing results
Number of solutions: 1
Solution Information
Gap: 0.0
Status: feasible
Function Value: 0.0
]
哪一行导致错误?哪一行导致错误?
param I : p b :=
"Andalucia" 845 40000
"Aragón" 132 35000
"Principado de Asturias" 275 10000
"Comunitat Valenciana" 500 40000
;
WARNING: Constant objective detected, replacing with a placeholder to prevent
solver failure.
WARNING: Empty constraint block written in LP format - solver may error
[ 0.05] Processing results
Number of solutions: 1
Solution Information
Gap: 0.0
Status: feasible
Function Value: 0.0
]