@Test
public void testSinZero() {
DifferentiableUnivariateFunction f = new Sin();
double result;
NewtonSolver solver = new NewtonSolver();
result = solver.solve(100, f, 3, 4);
Assert.assertEquals(result, FastMath.PI, solver.getAbsoluteAccuracy());
result = solver.solve(100, f, 1, 4);
Assert.assertEquals(result, FastMath.PI, solver.getAbsoluteAccuracy());
Assert.assertTrue(solver.getEvaluations() > 0);
}
@Test
public void testQuinticZero() {
final UnivariateDifferentiableFunction q = new QuinticFunction();
DifferentiableUnivariateFunction f =
new DifferentiableUnivariateFunction() {
public double value(double x) {
return q.value(x);
}
public UnivariateFunction derivative() {
return new UnivariateFunction() {
public double value(double x) {
return q.value(new DerivativeStructure(1, 1, 0, x)).getPartialDerivative(1);
}
};
}
};
double result;
NewtonSolver solver = new NewtonSolver();
result = solver.solve(100, f, -0.2, 0.2);
Assert.assertEquals(result, 0, solver.getAbsoluteAccuracy());
result = solver.solve(100, f, -0.1, 0.3);
Assert.assertEquals(result, 0, solver.getAbsoluteAccuracy());
result = solver.solve(100, f, -0.3, 0.45);
Assert.assertEquals(result, 0, solver.getAbsoluteAccuracy());
result = solver.solve(100, f, 0.3, 0.7);
Assert.assertEquals(result, 0.5, solver.getAbsoluteAccuracy());
result = solver.solve(100, f, 0.2, 0.6);
Assert.assertEquals(result, 0.5, solver.getAbsoluteAccuracy());
result = solver.solve(100, f, 0.05, 0.95);
Assert.assertEquals(result, 0.5, solver.getAbsoluteAccuracy());
result = solver.solve(100, f, 0.85, 1.25);
Assert.assertEquals(result, 1.0, solver.getAbsoluteAccuracy());
result = solver.solve(100, f, 0.8, 1.2);
Assert.assertEquals(result, 1.0, solver.getAbsoluteAccuracy());
result = solver.solve(100, f, 0.85, 1.75);
Assert.assertEquals(result, 1.0, solver.getAbsoluteAccuracy());
result = solver.solve(100, f, 0.55, 1.45);
Assert.assertEquals(result, 1.0, solver.getAbsoluteAccuracy());
result = solver.solve(100, f, 0.85, 5);
Assert.assertEquals(result, 1.0, solver.getAbsoluteAccuracy());
}
