利用最小二乘法进行拟合多元非线性方程，包括最小二乘法、SVM、神经网络、1_k近邻法,包含收发两个客户端的链路级通信程序。- Multivariate least squares fitting method of nonlinear equations, Including the least squares method, the SVM, neural networks, 1 _k neighbor method, Contains two clients receive link-lev