\begin{eqnarray*}
        \cos(\varphi) & = & \frac{v \cdot h}{\sqrt{\|v\|} \ast \sqrt{\|h\|}}\\
        & = & \frac{\sum_{i=1}^n{v_i \ast h_i}}{\sqrt{\sum_{i=1}^n{v^2_i}} \ast \sqrt{\sum_{i=1}^n{h^2_i}}}
\end{eqnarray*}