Class LinearOptimizationSolution

LinearOptimizationSolution

线性程序的解。以下示例求解了以下线性程序：

两个变量，x 和 y：
0 ≤ x ≤ 10
0 ≤ y ≤ 5

限制条件：
0 ≤ 2 * x + 5 * y ≤ 10
0 ≤ 10 * x + 3 * y ≤ 20

目标：
最大限度提高x + y 

var engine = LinearOptimizationService.createEngine();

// Add variables, constraints and define the objective with addVariable(), addConstraint(), etc.
// Add two variables, 0 <= x <= 10 and 0 <= y <= 5
engine.addVariable('x', 0, 10);
engine.addVariable('y', 0, 5);

// Create the constraint: 0 <= 2 * x + 5 * y <= 10
var constraint = engine.addConstraint(0, 10);
constraint.setCoefficient('x', 2);
constraint.setCoefficient('y', 5);

// Create the constraint: 0 <= 10 * x + 3 * y <= 20
var constraint = engine.addConstraint(0, 20);
constraint.setCoefficient('x', 10);
constraint.setCoefficient('y', 3);

// Set the objective to be x + y
engine.setObjectiveCoefficient('x', 1);
engine.setObjectiveCoefficient('y', 1);

// Engine should maximize the objective
engine.setMaximization();

// Solve the linear program
var solution = engine.solve();
if (!solution.isValid()) {
  Logger.log('No solution ' + solution.getStatus());
} else {
  Logger.log('Objective  value: ' + solution.getObjectiveValue());
  Logger.log('Value of x: ' + solution.getVariableValue('x'));
  Logger.log('Value of y: ' + solution.getVariableValue('y'));
}

方法

方法返回类型简介
getObjectiveValue()Number获取当前解决方案中目标函数的值。
getStatus()Status获取解决方案的状态。
getVariableValue(variableName)Number获取上次调用 LinearOptimizationEngine.solve() 所创建解决方案中某个变量的值。
isValid()Boolean确定解决方案是否可行还是最优。

详细文档

getObjectiveValue()

获取当前解决方案中目标函数的值。 

var engine = LinearOptimizationService.createEngine();

// Add variables, constraints and define the objective with addVariable(), addConstraint(), etc
engine.addVariable('x', 0, 10);

// ...

// Solve the linear program
var solution = engine.solve();
Logger.log('ObjectiveValue: ' + solution.getObjectiveValue());

返回

Number - 目标函数的值

getStatus()

获取解决方案的状态。在解题之前，状态将为 NOT_SOLVED。 

var engine = LinearOptimizationService.createEngine();

// Add variables, constraints and define the objective with addVariable(), addConstraint(), etc
engine.addVariable('x', 0, 10);

// ...

// Solve the linear program
var solution = engine.solve();
if (solution.getStatus() != LinearOptimizationService.Status.FEASIBLE &&
    solution.getStatus() != LinearOptimizationService.Status.OPTIMAL) {
  throw 'No solution ' + status;
}
Logger.log('Status: ' + solution.getStatus());

返回

Status - 求解器的状态

getVariableValue(variableName)

获取上次调用 LinearOptimizationEngine.solve() 所创建解决方案中某个变量的值。 

var engine = LinearOptimizationService.createEngine();

// Add variables, constraints and define the objective with addVariable(), addConstraint(), etc
engine.addVariable('x', 0, 10);

// ...

// Solve the linear program
var solution = engine.solve();
Logger.log('Value of x: ' + solution.getVariableValue('x'));

参数

名称类型说明
variableNameString变量的名称

返回

Number - 解决方案中变量的值

isValid()

确定解决方案是否可行还是最优。 

var engine = LinearOptimizationService.createEngine();

// Add variables, constraints and define the objective with addVariable(), addConstraint(), etc
engine.addVariable('x', 0, 10);

// ...

// Solve the linear program
var solution = engine.solve();
if (!solution.isValid()) {
  throw 'No solution ' + status;
}

返回

Boolean - 如果解决方案有效，则为 true（Status.FEASIBLE 或 Status.OPTIMAL);false（如果不是）