Class LinearOptimizationEngine

LinearOptimizationEngine

用于为线性程序建模和求解的引擎。下例解决 线性程序:

两个变量,xy
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('Value of x: ' + solution.getVariableValue('x'));
  Logger.log('Value of y: ' + solution.getVariableValue('y'));
}

方法

方法返回类型简介
addConstraint(lowerBound, upperBound)LinearOptimizationConstraint在模型中添加新的线性约束条件。
addConstraints(lowerBounds, upperBounds, variableNames, coefficients)LinearOptimizationEngine向模型批量添加约束条件。
addVariable(name, lowerBound, upperBound)LinearOptimizationEngine向模型添加新的连续变量。
addVariable(name, lowerBound, upperBound, type)LinearOptimizationEngine向模型添加新变量。
addVariable(name, lowerBound, upperBound, type, objectiveCoefficient)LinearOptimizationEngine向模型添加新变量。
addVariables(names, lowerBounds, upperBounds, types, objectiveCoefficients)LinearOptimizationEngine将变量批量添加到模型中。
setMaximization()LinearOptimizationEngine设置优化方向,以将线性目标函数最大化。
setMinimization()LinearOptimizationEngine将优化方向设置为最小化线性目标函数。
setObjectiveCoefficient(variableName, coefficient)LinearOptimizationEngine设置线性目标函数中变量的系数。
solve()LinearOptimizationSolution解当前的线性程序,其默认截止时间为 30 秒。
solve(seconds)LinearOptimizationSolution求解当前线性程序。

详细文档

addConstraint(lowerBound, upperBound)

在模型中添加新的线性约束条件。限制条件的上限和下限为 在创建时定义的名称变量的系数通过调用 LinearOptimizationConstraint.setCoefficient(variableName, coefficient) 来定义。

var engine = LinearOptimizationService.createEngine();

// Create a linear constraint with the bounds 0 and 10
var constraint = engine.addConstraint(0, 10);

// Create a variable so we can add it to the constraint
engine.addVariable('x', 0, 5);

// Set the coefficient of the variable in the constraint. The constraint is now:
// 0 <= 2 * x <= 5
constraint.setCoefficient('x', 2);

参数

名称类型说明
lowerBoundNumber约束条件的下限
upperBoundNumber约束条件的上限

返回

LinearOptimizationConstraint - 创建的限制条件


addConstraints(lowerBounds, upperBounds, variableNames, coefficients)

向模型批量添加约束条件。

var engine = LinearOptimizationService.createEngine();

// Add a boolean variable 'x' (integer >= 0 and <= 1) and a real (continuous >= 0 and <= 100)
variable 'y'.
engine.addVariables(['x', 'y'], [0, 0], [1, 100],
    [LinearOptimizationService.VariableType.INTEGER,
        LinearOptimizationService.VariableType.CONTINUOUS]);

// Adds two constraints:
//   0 <= x + y <= 3
//   1 <= 10 * x - y <= 5
engine.addConstraints([0.0, 1.0], [3.0, 5.0], [['x', 'y'], ['x', 'y']], [[1, 1], [10, -1]]);

参数

名称类型说明
lowerBoundsNumber[]限制条件的下限
upperBoundsNumber[]限制条件的上限
variableNamesString[][]要设置系数的变量的名称
coefficientsNumber[][]所设置的系数

返回

LinearOptimizationEngine - 线性优化引擎


addVariable(name, lowerBound, upperBound)

向模型添加新的连续变量。变量通过其名称引用。类型 设为 VariableType.CONTINUOUS

var engine = LinearOptimizationService.createEngine();
var constraint = engine.addConstraint(0, 10);

// Add a boolean variable (integer >= 0 and <= 1)
engine.addVariable('x', 0, 1, LinearOptimizationService.VariableType.INTEGER);

// Add a real (continuous) variable. Notice the lack of type specification.
engine.addVariable('y', 0, 100);

参数

名称类型说明
nameString变量的唯一名称
lowerBoundNumber变量的下限
upperBoundNumber变量的上限

返回

LinearOptimizationEngine - 线性优化引擎


addVariable(name, lowerBound, upperBound, type)

向模型添加新变量。变量是通过其名称引用的。

var engine = LinearOptimizationService.createEngine();
var constraint = engine.addConstraint(0, 10);

// Add a boolean variable (integer >= 0 and <= 1)
engine.addVariable('x', 0, 1, LinearOptimizationService.VariableType.INTEGER);

// Add a real (continuous) variable
engine.addVariable('y', 0, 100, LinearOptimizationService.VariableType.CONTINUOUS);

参数

名称类型说明
nameString变量的唯一名称
lowerBoundNumber变量的下限
upperBoundNumber变量的上限
typeVariableType变量的类型,可以是以下值之一:VariableType

返回

LinearOptimizationEngine - 线性优化引擎


addVariable(name, lowerBound, upperBound, type, objectiveCoefficient)

向模型添加新变量。变量通过其名称引用。

var engine = LinearOptimizationService.createEngine();
var constraint = engine.addConstraint(0, 10);

// Add a boolean variable (integer >= 0 and <= 1)
engine.addVariable('x', 0, 1, LinearOptimizationService.VariableType.INTEGER, 2);
// The objective is now 2 * x.

// Add a real (continuous) variable
engine.addVariable('y', 0, 100, LinearOptimizationService.VariableType.CONTINUOUS, -5);
// The objective is now 2 * x - 5 * y.

参数

名称类型说明
nameString变量的唯一名称
lowerBoundNumber变量的下限
upperBoundNumber变量的上限
typeVariableType变量的类型,可以是以下值之一:VariableType
objectiveCoefficientNumber变量的目标系数

返回

LinearOptimizationEngine - 线性优化引擎


addVariables(names, lowerBounds, upperBounds, types, objectiveCoefficients)

将变量批量添加到模型中。变量通过其名称引用。

var engine = LinearOptimizationService.createEngine();

// Add a boolean variable 'x' (integer >= 0 and <= 1) and a real (continuous >=0 and <= 100)
// variable 'y'.
engine.addVariables(['x', 'y'], [0, 0], [1, 100],
    [LinearOptimizationService.VariableType.INTEGER,
        LinearOptimizationService.VariableType.CONTINUOUS]);

参数

名称类型说明
namesString[]变量的唯一名称
lowerBoundsNumber[]变量的下限
upperBoundsNumber[]变量的上限
typesVariableType[]变量的类型,可以是以下之一:VariableType
objectiveCoefficientsNumber[]变量的客观系数

返回

LinearOptimizationEngine - 线性优化引擎


setMaximization()

设置优化方向,以将线性目标函数最大化。

var engine = LinearOptimizationService.createEngine();

// Add a real (continuous) variable. Notice the lack of type specification.
engine.addVariable('y', 0, 100);

// Set the coefficient of 'y' in the objective.
// The objective is now 5 * y
engine.setObjectiveCoefficient('y', 5);

// We want to maximize.
engine.setMaximization();

返回

LinearOptimizationEngine - 线性优化引擎


setMinimization()

将优化方向设置为最小化线性目标函数。

var engine = LinearOptimizationService.createEngine();

// Add a real (continuous) variable. Notice the lack of type specification.
engine.addVariable('y', 0, 100);

// Set the coefficient of 'y' in the objective.
// The objective is now 5 * y
engine.setObjectiveCoefficient('y', 5);

// We want to minimize
engine.setMinimization();

返回

LinearOptimizationEngine - 线性优化引擎


setObjectiveCoefficient(variableName, coefficient)

设置线性目标函数中变量的系数。

var engine = LinearOptimizationService.createEngine();

// Add a real (continuous) variable. Notice the lack of type specification.
engine.addVariable('y', 0, 100);

// Set the coefficient of 'y' in the objective.
// The objective is now 5 * y
engine.setObjectiveCoefficient('y', 5);

参数

名称类型说明
variableNameString要设置系数的变量的名称
coefficientNumber目标函数中变量的系数

返回

LinearOptimizationEngine - 线性优化引擎


solve()

解当前的线性程序,其默认截止时间为 30 秒。返回找到的解。

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 ' + solution.getStatus();
}
Logger.log('Value of x: ' + solution.getVariableValue('x'));

返回

LinearOptimizationSolution - 优化解决方案


solve(seconds)

求解当前线性程序。返回找到的解。如果它是 解决方案。

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(300);
if (!solution.isValid()) {
  throw 'No solution ' + solution.getStatus();
}
Logger.log('Value of x: ' + solution.getVariableValue('x'));

参数

名称类型说明
secondsNumber解决问题的期限(以秒为单位);最长时限为 300 秒

返回

LinearOptimizationSolution - 优化解决方案