GUROBI之常用Attributes总结

总结了一下目前模型、变量、目标函数等比较常用的属性，后续遇到了其他了会陆续补充

完整的详见官网：Attributes - Gurobi Optimization

Model attributes:

Attribute name	Description
NumVars	Number of variables
NumConstrs	Number of linear constraints
ModelName	Model name
ModelSense	Model sense (minimization or maximization)
ObjVal	Objective value for current solution
Status	Current optimization status

Model.getAttr()

getAttr ( attrname, objs=None )

Arguments:

attrname: Name of the attribute.

objs (optional): List or dictionary containing either constraints or variables

Example usage:

  print(model.numintvars)
  print(model.getAttr("numIntVars"))
  print(model.getAttr(GRB.Attr.NumIntVars))
  print(model.getAttr("X", model.getVars()))
  print(model.getAttr("Pi", model.getConstrs()))

Variable attributes:

Attribute name	Description
LB	Lower bound
UB	Upper bound
Obj	Linear objective coefficient
VType	Variable type (continuous, binary, integer, etc.)
VarName	Variable name
X	Value in the current solution
Xn	Value in a sub-optimal MIP solution

Var.getAttr()

getAttr ( attrname )

Arguments:

attrname: The attribute being queried.

Return value:

The current value of the requested attribute.

Example usage:

  print(var.getAttr(GRB.Attr.X))
  print(var.getAttr("x"))

Linear constraint attributes:(其他类型约束类似)

Attribute name	Description
Sense	Constraint sense ('<', '>', or '=')
RHS	Right-hand side value
ConstrName	Constraint name
Pi	Dual value (also known as the shadow price)
Slack	Slack in the current solution (松弛约束)

Constr.getAttr()

getAttr ( attrname )

Arguments:

attrname: The attribute being queried.

Return value:

The current value of the requested attribute.

Example usage:

  print(constr.getAttr(GRB.Attr.Slack))
  print(constr.getAttr("slack"))

Multi-objective attributes:

Attribute name	Description
ObjN	Objectives of multi-objectives
ObjNCon	Constant terms of multi-objectives
ObjNPriority	Priorities of multi-objectives
ObjNWeight	Weights of multi-objectives
ObjNVal	Objective value of multi-objectives solutions
ObjNName	Names of multi-objectives
NumObj	Number of multi-objectives