核函数是利用支持向量机解决不可分问题时引入的一种非线性变换的手段。基本思想是通过非线性变换，使样本变换之后的特征空间中变得线性可分。然后利用线性可分时构造最优超平面的方法，在特征空间中实现最优超平面的求解。-Kernel function is the use of support vector machine to resolve the issue can not be separated from the introduction of a nonlinear transform means. Basic idea is to adoption of non-linear transform, so that after changing the characteristics of the sample space become linearly separable. And the use of linear time-structure optimal hyperplane method of implementation in the feature space for solving the optimal hyperplane.