kubispline
Kubispline, also known as cubic spline interpolation, is a method for constructing a smooth curve that passes through a set of given data points. It is a piecewise polynomial interpolation, meaning it uses a different cubic polynomial to connect each pair of adjacent data points. The key characteristic of a kubispline is that not only do the polynomial pieces match the function values at the data points, but their first and second derivatives also match at these points. This ensures that the resulting curve is continuous and has a smooth, continuous slope and curvature, avoiding sharp corners or abrupt changes.
There are several types of kubisplines, distinguished by their boundary conditions. Natural cubic splines, for example,