/// <summary>
/// Applies a perturbation to the specified underlying.
/// <para>
/// This should be invoked once for each of the underlying instances.
/// It is intended to be used to pass the result of each invocation to the
/// constructor of the combined instance.
///
/// </para>
/// </summary>
/// @param <R> the type of the underlying </param>
/// <param name="underlyingIndex"> the index of the underlying instance </param>
/// <param name="underlyingType"> the type of the parameterized data at the specified index </param>
/// <param name="perturbation"> the perturbation to apply </param>
/// <returns> a parameterized data instance based on this with the specified perturbation applied </returns>
public R underlyingWithPerturbation <R>(int underlyingIndex, Type <R> underlyingType, ParameterPerturbation perturbation) where R : ParameterizedData
{
ParameterizedData underlying = underlyings[underlyingIndex];
// perturb using a derived perturbation that adjusts the index
int adjustment = lookup[underlyingIndex];
ParameterizedData perturbed = underlying.withPerturbation((idx, value, meta) => perturbation(idx + adjustment, value, meta));
return(underlyingType.cast(perturbed));
}
public virtual void test_withPerturbation()
{
assertSame(CURVE.withPerturbation((i, v, m) => v), CURVE);
assertEquals(CURVE.withPerturbation((i, v, m) => v + 2d).getParameter(0), 3d);
}
