A spline is a series of polynomials joined at knots. Splines can be useful in scenarios where using a single approximating polynomial is impractical.

Curve Fitting Toolbox™ functions allow you to construct splines for fitting to and smoothing data. For more information, see How to Construct Splines. Splines can be used to smooth noisy data and perform interpolation. For a simple example showing how to use splines to perform interpolation, see Cubic Spline Interpolation.

Using the Curve Fitter app or the fit function, you can fit cubic spline interpolants, smoothing splines, and thin-plate splines. Other Curve Fitting Toolbox functions allows more specialized control over spline construction. For information, see Introducing Spline Fitting.