Class FDistribution

java.lang.Object
cloud.opencode.base.math.distribution.FDistribution
public final class FDistribution extends Object
Immutable F-distribution (Fisher-Snedecor distribution). 不可变 F 分布（Fisher-Snedecor 分布）

Provides PDF, CDF, and inverse CDF (quantile function). Thread-safe: instances are immutable.

提供概率密度函数、累积分布函数和逆累积分布函数（分位函数）。 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(double x)
    Computes the cumulative distribution function (CDF) at x.
    double
    denominatorDf()
    Returns the denominator degrees of freedom.
    double
    inverseCdf(double p)
    Computes the inverse CDF (quantile function).
    double
    numeratorDf()
    Returns the numerator degrees of freedom.
    static FDistribution
    of(double df1, double df2)
    Creates an F-distribution with the specified degrees of freedom.
    double
    pdf(double x)
    Computes the probability density function (PDF) at x.
    String
    toString()
     

    Methods inherited from class Object

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

  • Method Details

    • of

      public static FDistribution of(double df1, double df2)
      Creates an F-distribution with the specified degrees of freedom. 创建具有指定自由度的 F 分布
      Parameters:
      df1 - numerator degrees of freedom, must be > 0 / 分子自由度，必须 > 0
      df2 - denominator degrees of freedom, must be > 0 / 分母自由度，必须 > 0
      Returns:
      a new FDistribution instance / 新的 F 分布实例
      Throws:
      IllegalArgumentException - if df1 or df2 ≤ 0 or not finite

    • numeratorDf

      public double numeratorDf()
      Returns the numerator degrees of freedom. 返回分子自由度
      Returns:
      the numerator degrees of freedom / 分子自由度

    • denominatorDf

      public double denominatorDf()
      Returns the denominator degrees of freedom. 返回分母自由度
      Returns:
      the denominator degrees of freedom / 分母自由度

    • pdf

      public double pdf(double x)
      Computes the probability density function (PDF) at x. 计算在 x 处的概率密度函数值
      Parameters:
      x - the point at which to evaluate the PDF / 计算 PDF 的点
      Returns:
      the density at x / x 处的密度值

    • cdf

      public double cdf(double x)
      Computes the cumulative distribution function (CDF) at x. 计算在 x 处的累积分布函数值

      F(x) = I(df1*x/(df1*x+df2), df1/2, df2/2) where I is the regularized incomplete beta function.

      Parameters:
      x - the point at which to evaluate the CDF / 计算 CDF 的点
      Returns:
      the cumulative probability P(X ≤ x) / 累积概率

    • inverseCdf

      public double inverseCdf(double p)
      Computes the inverse CDF (quantile function). 计算逆累积分布函数（分位函数）
      Parameters:
      p - the cumulative probability, must be in (0, 1) / 累积概率，必须在 (0, 1) 内
      Returns:
      the quantile x such that P(X ≤ x) = p / 使得 P(X ≤ x) = p 的分位数
      Throws:
      MathException - if p is not in (0, 1)

    • toString

      public String toString()
      Overrides:
      toString in class Object