MATLAB simulation of curve fitting based onleast-squares

In scientific experiments and applications,based on analyzing a set of test data to seek approximate function relational expression between the independent variables and the dependent variable is often necessary.So that it can easily be used in computer or by other designer for other design or calculation,such problem is the curve fitting by the set of test data.In the field of system identification,because more accurate and practical,least squares curve fitting is widely used as the most commonly used method.The principle of curve fitting based on least squares method is introduced in this paper.The method of curve fitting by function,the method of curve fitting by graphical interface and the method of curve fitting by Fitting Toolbox are analyzed by examples specifically.The effects and characteristics of various methods of fitting are compared and analyzed in this paper.The following conclusions by analyzing,there is need for a better understanding of fitting function and the related programs are written used the method of curve fitting by function.This method is more flexible.The characteristics are intuitive,simple and the parameters and residuals of fitting equation can be obtained by using the method of curve fitting by graphical interface or by Fitting Toolbox.Fitting accuracy is high and the effect is good.