Class RombergIntegrator

  • public class RombergIntegratorextends IterativeMethod

    An implementation of Romberg Integration.

    For example, to evaluate definite integrals for sine, first a Function is defined:

     Function sine = new Function() {    public double evaluate(double x) {        return Math.sin(x);    }} }; 

    Then, a Romberg integrator is created with the above function:

     RombergIntegrator integrator = new RombergIntegrator(sine); 

    Lastly, evaluating definite integrals is accomplished using the integrate(double, double) method:

     // integrate sine from 0 to Pi. double two = integrator.integrate(0.0, Math.PI);  // integrate sine from Pi/2 to 2 Pi. double one = integrator.integrate(Math.PI / 2.0, Math.PI); 


    1. Eric W. Weisstein. "Romberg Integration." From MathWorld--A Wolfram Web Resource.

    • Constructor Detail

      • RombergIntegrator

        public RombergIntegrator(Function f)
        Create an integrator for the given function.
        f - the target function.
      • RombergIntegrator

        public RombergIntegrator(Function f,                 int iterations,                 double error)
        Create an integrator for the given function.
        f - the target function.
        iterations - maximum number of iterations.
        error - maximum relative error.
    • Method Detail

      • getFunction

        public Function getFunction()
        Access the target function.
        the target function.
      • integrate

        public double integrate(double a,               double b)                 throws NumericException
        Evaluate the definite integral from a to b.
        a - the lower limit of integration.
        b - the upper limit of integration.
        the definite integral from a to b.
        NumericException - if the integral can not be evaluated.
      • setFunction

        public void setFunction(Function f)
        Modify the target function.
        f - the new target function.

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