如何将一个方程分成两行或三行？

Question

我有以下等式

\begin{equation}\label{eq:36}
\emph{$SINR^{D,UL}_{k,n}$} =  \frac{p_{k,n} |h_{k,n}|^2}{\sum_{m=1}^{M} \omega_{n,m}p_{m,n}|h^{C}_{m,n}|^2   + \sum_{c^{'}=1}^{C^{'}} \sum_{m^{'}}^{M^{'}} \omega^{'}_{n,m^{'},c^{'}}p_{m^{'},n}|h^{C}_{m^{'},n,k,c^{'}}|^2   + \sum_{c^{'}=1}^{C^{'}} \sum_{k^{'}}^{K^{'}} \zeta^{'}_{n,k^{'},c^{'}}p_{k^{'},n}|h^{D}_{k^{'},n,k,c^{'}}|^2  + N_{0}B}  
\end{equation}

该方程式不太适合用一行来表达。我怎样才能将其分成两行或三行？请参阅我的图表示例。

多谢。

Answer 1

也许使用multline？

\documentclass{article}
\usepackage{amsmath}
\newcommand\abs[1]{\lvert#1\rvert}
\begin{document}

\begin{multline}
  \label{eq:36}
  \mathrm{SINR}^{D,UL}_{k,n} =  p_{k,n} \abs{h_{k,n}}^2
  \biggl(
  \sum_{m=1}^{M} \omega_{n,m} p_{m,n} \abs{h^{C}_{m,n}}^2 \\
  + \sum_{c'=1}^{C'} \sum_{m'}^{M'} \omega'_{n,m',c'} p_{m',n} \abs{h^{C}_{m',n,k,c'}}^2 \\
  + \sum_{c'=1}^{C'} \sum_{k'}^{K'} \zeta'_{n,k',c'} p_{k',n} \abs{h^{D}_{k',n,k,c'}}^2
  + N_{0}B
  \biggr)^{\!-1}
\end{multline}

\end{document}

或者引入别名：

\documentclass{article}
\usepackage{amsmath}
\newcommand\abs[1]{\lvert#1\rvert}
\begin{document}

\begin{equation}
  \label{eq:36}
  \mathrm{SINR}^{D,UL}_{k,n} =  \frac{p_{k,n} \abs{h_{k,n}}^2}{X + Y + Z + N_{0}B}
\end{equation}
where
\begin{align*}
  X &= \sum_{m=1}^{M} \omega_{n,m} p_{m,n} \abs{h^{C}_{m,n}}^2 \\
  Y &= \sum_{c'=1}^{C'} \sum_{m'}^{M'} \omega'_{n,m',c'} p_{m',n} \abs{h^{C}_{m',n,k,c'}}^2 \\
  Z &= \sum_{c'=1}^{C'} \sum_{k'}^{K'} \zeta'_{n,k',c'} p_{k',n} \abs{h^{D}_{k',n,k,c'}}^2
\end{align*}

\end{document}

你也可以做出问题中所展示的令人讨厌的事情，但我不建议这样做。

\documentclass{article}
\usepackage{amsmath}
\newcommand\abs[1]{\lvert#1\rvert}
\begin{document}

\begin{equation}
  \label{eq:36}
  \mathrm{SINR}^{D,UL}_{k,n} =  \frac{p_{k,n} \abs{h_{k,n}}^2}{
    \begin{pmatrix}
      \sum_{m=1}^{M} \omega_{n,m} p_{m,n} \abs{h^{C}_{m,n}}^2 + {} \\
      \sum_{c'=1}^{C'} \sum_{m'}^{M'} \omega'_{n,m',c'} p_{m',n} \abs{h^{C}_{m',n,k,c'}}^2 + {} \\
      \sum_{c'=1}^{C'} \sum_{k'}^{K'} \zeta'_{n,k',c'} p_{k',n} \abs{h^{D}_{k',n,k,c'}}^2 + N_{0}B
    \end{pmatrix}
  }
\end{equation}

\end{document}