筷点雪糕侠

摘要： 考虑$y(x),y(x')$间的协方差 \(\begin{eqnarray} cov[y(x),y(x')] &=& cov[\phi(x)^Tw,w^T\phi(x')] \ &=& \phi(x)^TS_N\phi(x') = \beta^{-1}k(x,x') \tag{3.63} \end{ 阅读全文