MathWorks - Curve Fitting Toolbox

The Curve Fitting Toolbox is a collection of MATLAB® functions that provides a central access point for curve fitting applications. The toolbox provides routines for preprocessing data, as well as creating, comparing, analyzing, and managing models. The functionality in the Curve Fitting Toolbox is available through an intuitive visual interface or at the command line. In addition, toolbox functions are implemented in the open MATLAB language. This gives you access to the source code, which allows you to learn from and customize existing algorithms or develop your own.