Adaptive Integrator

The net.sf.doodleproject.numerics4j.integration.AdaptiveIntegrator class provides an implementation of Adaptive Quadrature.

Evaluating definite integrals using adaptive quadrature involves creating a AdaptiveIntegrator object for a particular net.sf.doodleproject.numerics4j.function.Function object. Once, the integrator is created, definite integrals can be evaluated by calling the integrate method providing the limits of integration. Here is an example of evaluating integrals for sine: 

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

AdaptiveIntegrator integrator = new AdaptiveIntegrator(sine);

// 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);