在 Sigma 上获取符号

Question

尝试让这个方程在乳胶中工作，但在工作中遇到困难，我尝试了以下方法

\begin{equation}
  \mathlarger {( I * K)_{xy} = \Sigma^{h}_{i=1} \Sigma^{w}_{j=1} K}
\end{equation}{}

Answer 1

正确的符号是\sum（表示“求和”），而不是\Sigma。也没有理由\mathlarger。不要{}在 后面添加\end{equation}。

\documentclass{article}
\usepackage{amsmath} % recommended
\usepackage{relsize} % for \mathlarger

\begin{document}

The following display is wrong under many respects: the symbol
should be \verb|\sum| and not \verb|\Sigma|; also there is no
reason to make the symbols larger.
\begin{equation}
  \mathlarger {( I * K)_{xy} = \Sigma^{h}_{i=1} \Sigma^{w}_{j=1} K}
\end{equation}{}
This is the correct way to typeset the formula
\begin{equation}
(I * K)_{xy} = \sum^{h}_{i=1} \sum^{w}_{j=1} K
\end{equation}
Note that the empty group like in \verb|\end{equation}{}| is 
actually harmful: can you spot the misalignment?

\end{document}