Class BinomialDistribution

java.lang.Object
cloud.opencode.base.math.distribution.BinomialDistribution
public final class BinomialDistribution extends Object
Immutable binomial distribution. 不可变二项分布

Provides PMF, CDF, mean, and variance. Thread-safe: instances are immutable.

提供概率质量函数、累积分布函数、均值和方差。 线程安全：实例不可变。

Since:
JDK 25, opencode-base-math V1.0.3
Author:
Leon Soo www.LeonSoo.com
See Also:

  • Method Summary

    Modifier and Type
    Method
    Description
    double
    cdf(int k)
    Computes the cumulative distribution function (CDF) at k: P(X ≤ k).
    double
    mean()
    Returns the mean of this distribution: n * p.
    static BinomialDistribution
    of(int n, double p)
    Creates a binomial distribution with the specified parameters.
    double
    pmf(int k)
    Computes the probability mass function (PMF) at k.
    double
    probability()
    Returns the probability of success.
    String
    toString()
     
    int
    trials()
    Returns the number of trials.
    double
    variance()
    Returns the variance of this distribution: n * p * (1 - p).

    Methods inherited from class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Method Details

    • of

      public static BinomialDistribution of(int n, double p)
      Creates a binomial distribution with the specified parameters. 创建具有指定参数的二项分布
      Parameters:
      n - the number of trials, must be ≥ 0 / 试验次数，必须 ≥ 0
      p - the probability of success, must be in [0, 1] / 成功概率，必须在 [0, 1] 内
      Returns:
      a new BinomialDistribution instance / 新的二项分布实例
      Throws:
      IllegalArgumentException - if n < 0 or p is not in [0, 1]

    • trials

      public int trials()
      Returns the number of trials. 返回试验次数
      Returns:
      the number of trials / 试验次数

    • probability

      public double probability()
      Returns the probability of success. 返回成功概率
      Returns:
      the probability of success / 成功概率

    • mean

      public double mean()
      Returns the mean of this distribution: n * p. 返回此分布的均值：n * p
      Returns:
      the mean / 均值

    • variance

      public double variance()
      Returns the variance of this distribution: n * p * (1 - p). 返回此分布的方差：n * p * (1 - p)
      Returns:
      the variance / 方差

    • pmf

      public double pmf(int k)
      Computes the probability mass function (PMF) at k. 计算在 k 处的概率质量函数值

      P(X = k) = C(n, k) * p^k * (1 - p)^(n - k), computed in log-space.

      Parameters:
      k - the number of successes / 成功次数
      Returns:
      the probability P(X = k) / 概率 P(X = k)

    • cdf

      public double cdf(int k)
      Computes the cumulative distribution function (CDF) at k: P(X ≤ k). 计算在 k 处的累积分布函数值：P(X ≤ k)

      Uses the regularized incomplete beta function for efficiency: P(X ≤ k) = I(1-p, n-k, k+1).

      Parameters:
      k - the upper limit / 上限
      Returns:
      the cumulative probability P(X ≤ k) / 累积概率

    • toString

      public String toString()
      Overrides:
      toString in class Object