In mathematics, a spline is a special function defined piecewise by polynomials. In interpolating problems, spline interpolation is often preferred to polynomial interpolation because it yields similar results, even when using low-degree polynomials, while avoiding Runge's phenomenon for higher degrees.

What is spline approximation used for?

The approximate representation of a function, or the approximate reconstruction of a function in a given class from incomplete information (for example, from its values on a set of points), using splines (cf. Spline).

Why is cubic spline interpolation better?

Given equally spaced sample values of a function , one can approximate as the polynomial of degree that passes through all points on a plot. ... On the other hand, cubic spline interpolation is often considered a better approximation method because it is not prone to such oscillations.