Class Trigamma


  • public final class Trigamma
    extends java.lang.Object
    Trigamma function. It is the derivative of the digamma function: \( \psi_1(x) = \frac{d^2}{dx^2} (\ln \Gamma(x)) \).
    • Field Summary

      Fields 
      Modifier and Type Field Description
      private static double C_LIMIT
      C limit.
      private static double F_1_30
      Fraction.
      private static double F_1_42
      Fraction.
      private static double F_1_6
      Fraction.
      private static double S_LIMIT
      S limit.
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      private Trigamma()
      Private constructor.
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static double value​(double x)
      Computes the trigamma function.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • Trigamma

        private Trigamma()
        Private constructor.
    • Method Detail

      • value

        public static double value​(double x)
        Computes the trigamma function.
        Parameters:
        x - Argument.
        Returns:
        trigamma(x) to within 1e-8 relative or absolute error whichever is larger.