对于数据处理，常常要用到数据的曲线拟合，matlab中给出了拟合函数后，如果知道x，可以很快地求y,但若知道一个y要求x是不容易的，所以给出了一个1阶傅立叶拟合的范例，可推广至多阶fourier的曲线拟合。

MATLAB软件提供了基本的曲线拟合函数的命令．但好多人并不清楚函数的选择！

matlab 多项式拟合函数 ployfit 的C语言代码

该代码为神经网络（BP/RBF）拟合典型函数曲线的经典程序，为matlab语言编写。

神经网络拟合函数的简单程序，matlab语言编写。

对于一个二元非线性函数z=f(x,y),构建神经网络并对其进行训练，使其在定义域内对此二元函数进行拟合。主函数是bp2.py，配好环境解压后直接打开运行即可，现在是迭代20次，如果需要换函数，修改21行的z[j][i]

BP神经网络的理论介绍，公式推演，以及通过拟合函数实例进行仿真模拟

文件中包含有BP神经网络拟合曲线函数实例的matlab代码，word文档一份内容为作业，一份内容为答案.

最小二乘法拟合 用高斯牛顿法 一个指数函数 一个抛物线拟合 能运行 有结果

% This folder contains a collection of "fitting" functions. % (Some has demo options - the third section) % The GENERAL input to the functions should be samples of the distribution. % % for example, if we are to fit a normal distribution ('gaussian') with a mean "u" and varaince "sig"^2 % then the samples will distribute like: % samples = randn(1,10000)*sig + u % %fitting with Least-Squares is done on the histogram of the samples. % fitting with Maximum likelihood is done directly on the samples. % % % Contents of this folder % ======================= % 1) Maximum likelihood estimators % 2) Least squares estimators % 3) EM algorithm for estimation of multivariant gaussian distribution (mixed gaussians) % 4) added folders: Create - which create samples for the EM algorithm test % Plot - used to plot each of the distributions (parametric plot) % % % % % % Maximum likelihood estimators % ============================= % fit_ML_maxwell - fit maxwellian distribution % fit_ML_rayleigh - fit rayleigh distribution % (which is for example: sqrt(abs(randn)^2+abs(randn)^2)) % fit_ML_laplace - fit laplace distribution % fit_ML_log_normal- fit log-normal distribution % fit_ML_normal - fit normal (gaussian) distribution % % NOTE: all estimators are efficient estimators. for this reason, the distribution % might be written in a different way, for example, the "Rayleigh" distribution % is given with a parameter "s" and not "s^2". % % % least squares estimators % ========================= % fit_maxwell_pdf - fits a given curve of a maxwellian distribution % fit_rayleigh_pdf - fits a given curve of a rayleigh distribution % % NOTE: these fit function are used on a histogram output which is like a sampled % distribution function. the given curve MUST be normalized, since the estimator % is trying to fit a normalized distribution function. % % % % % Multivariant Gaussian distribution % ================================== % for demo of 1