Every basis of a linear space contains the same number of vectors. 一线性空间的每一基底包含同样数目的向量。
As for the undivided linear sample space, the kernel function is needed to map onto another high dimension linear space. 对于线性不可分的样本空间，需要寻找核函数，将线性不可分的样本集映射到另一个高维线性空间。
