also, extend the unit test for it. (*phew* that was much more fun than
appreciated because of all the index shifts. I'm still not 100% sure
that everything works in all corner cases, but at least my confidence
is at 95%.)
most of these issues are fallout from the conversion of the spline
class from a moments (second derivative) based approach to hermite
base functions:
- the second and third derivatives where incorrect, and the third
derivative was not available in the public interface.
- The unit test did not check the derivatives
- The coefficients for the monomial basis were off by the factors
stemming from the derivatives
- The intersectIntervall_() method used std::max() instead of
std::min() at one place and still added the base offset for the x
values as indicated by Stoer
