The tea-coffee example shows that high-confidence rules can sometimes be misleading. • This is because the confidence measure ignores the support of the itemset appearing in the rule consequent. • One way to address this problem is by applying a metric known as lift • This metric computes the ratio between • The rule’s confidence and • The support of the itemset in the rule consequent. ( ) ( ) Lift cA B s B → =

茶咖啡的例子说明了高置信度规则有时可能会误导。

这是因为置信度度量忽略了规则后件中出现的项目集的支持度。

解决这个问题的方法之一是应用一种称为提升度的度量。

该度量计算以下两者之比：

- 规则的置信度
- 规则后件中项目集的支持度

提升度公式为：

Lift(A → B) = (support(A ∪ B) / N) / (support(A) / N) × (support(B) / N) / N

其中，support(A ∪ B) 表示同时包含 A 和 B 的交易数，support(A) 和 support(B) 分别表示包含 A 和 B 的交易数，N 表示总交易数。

如果 Lift 大于 1，说明 A 和 B 之间存在正相关关系；如果 Lift 小于 1，说明 A 和 B 之间存在负相关关系；如果 Lift 等于 1，说明 A 和 B 之间相互独立。

相关问题

prediction from a rank-deficient fit may be misleading

这不是一个问题，这是一个陈述。这是一个统计学中的警告，意思是从一个秩不足的拟合中得出的预测可能是误导性的。在统计学中，如果一个模型中有太多的自变量与样本量相比，那么这个模型就被称为秩不足。这种情况下，模型可能会过度拟合数据，导致预测结果的不确定性增加。因此，在使用这样的模型进行预测时，需要谨慎对待结果并进行额外的验证。

Write the following code using c #, Write a method with the following specifications: name: DisplayEquation arguments: none return value: nothing displays: the following table: x 5 3x -2x^2 y 0.0 5.0 0.0 0.0 5.0 0.3 5.0 0.8 -0.1 5.6 0.5 5.0 1.5 -0.5 6.0 0.8 5.0 2.3 -1.1 6.1 1.0 5.0 3.0 -2.0 6.0 1.3 5.0 3.8 -3.1 5.6 1.5 5.0 4.5 -4.5 5.0 1.8 5.0 5.3 -6.1 4.1 2.0 5.0 6.0 -8.0 3.0 This table is calculated using the quadratic equation y = 5 + 3x -2x2 The value of x starts at 0 and moves in increments of 0.25 to 2.0. (The first column is misleading because the last digit is rounded up i.e. 0.25 is displayed as 0.3and. 0.75 is displayed as 0.8) Modify your DisplayMenu method by adding another choice below the last item. In your main when the user enters the appropriate choice in response to the menu choices, you will invoke this method and to display the above values

Here's the C# code for the DisplayEquation method:

public static void DisplayEquation()
{
    Console.WriteLine("x\t5\t3x\t-2x^2\ty");
    double x = 0.0;
    while (x <= 2.0)
    {
        double y = 5 + 3 * x - 2 * x * x;
        Console.WriteLine($"{x:f1}\t5.0\t{3*x:f1}\t{-2*x*x:f1}\t{y:f1}");
        x += 0.25;
    }
}

And here's an updated version of the DisplayMenu method that includes the new choice for displaying the equation table:

public static void DisplayMenu()
{
    Console.WriteLine("Choose an option:");
    Console.WriteLine("1. Display Hello World");
    Console.WriteLine("2. Display the current time");
    Console.WriteLine("3. Display the quadratic equation table");
    int choice = int.Parse(Console.ReadLine());
    switch (choice)
    {
        case 1:
            Console.WriteLine("Hello World!");
            break;
        case 2:
            Console.WriteLine($"The current time is {DateTime.Now}");
            break;
        case 3:
            DisplayEquation();
            break;
        default:
            Console.WriteLine("Invalid choice");
            break;
    }
}

To call the DisplayEquation method, you can simply add a new case to the switch statement in your main method:

while (true)
{
    DisplayMenu();
    Console.WriteLine("Press any key to continue...");
    Console.ReadKey();
}

And when the user enters "3" at the menu, the quadratic equation table will be displayed.