![长等式中分数不起作用](https://linux22.com/image/399729/%E9%95%BF%E7%AD%89%E5%BC%8F%E4%B8%AD%E5%88%86%E6%95%B0%E4%B8%8D%E8%B5%B7%E4%BD%9C%E7%94%A8.png)
到目前为止,我有这个:
\begin{equation}\label{EEDIeq}
\resizebox{0.85\hsize}{!}{\frac{{\Bigg(\prod_{j=1}^n f_j\Bigg)
\Bigg(\sum_{i=1}^{nME}P_{ME(i)}.C_{FME(i)}.SFC_{ME(i)}\Bigg) +
(P_{AE}.C_{FAE}.SFC_{AE})+
\Bigg(\Bigg(\prod_{j=1}^n f_j.\sum_{i=1}^{nPTI} P_{PTI(i)}-
\sum_{i=1}^{neff}f_{eff(i)}.P_{AEeff(i)}\Bigg)
C_{FAE}.SFC_{AE}\Bigg) -
\Bigg(\sum_{i=1}^{neff}f_{eff(i)}.P_{eff(i)}.C_{FME}.SFC_{ME}\Bigg)}}{f_i.f_c.f_l.Capacity.f_w.V_{ref}}}
\end{equation}
但我无法得到我想要的分母:
我该如何修复这个问题?谢谢 :)
答案1
您不应该强迫读者寻找放大镜;最好将内容分成几行。
\documentclass{article}
\usepackage{amsmath,mathtools}
\newcommand{\vr}[1]{\mathit{#1}}
\begin{document}
\begin{equation}\label{EEDIeq}
\begin{split}
&\frac{1}{f_i\cdot f_c\cdot f_l\cdot \vr{Capacity}\cdot f_w\cdot V_{\vr{ref}}} \\
& \cdot\biggl[
\biggl(\,\prod_{j=1}^n f_j\biggr)
\biggl(\,\sum_{i=1}^{n_{\vr{ME}}} P_{\vr{ME}(i)}\cdot
C_{\vr{FME}(i)}\cdot \vr{SFC}_{\vr{ME}(i)}\biggr)\\
&\qquad +
(P_{\vr{AE}}\cdot C_{\vr{FAE}}\cdot \vr{SFC}_{\vr{AE}}) \\
&\qquad +
\biggl(\biggl(\,\prod_{j=1}^n f_j\cdot \sum_{i=1}^{n_{\vr{PTI}}} P_{\vr{PTI}(i)}-
\sum_{i=1}^{n_{\vr{eff}}} f_{\vr{eff}(i)}\cdot P_{\vr{AEeff}(i)}\biggr)
C_{\vr{FAE}}\cdot \vr{SFC}_{\vr{AE}}\biggr) \\
&\qquad -
\biggl(\,\sum_{i=1}^{n_{\vr{eff}}} f_{\vr{eff}(i)}\cdot P_{\vr{eff}(i)}\cdot
C_{\vr{FME}}\cdot \vr{SFC}_{\vr{ME}}\biggr)
\biggr]
\end{split}
\end{equation}
\end{document}
应该更详细地研究上标的格式。切勿使用句号来表示乘法。
答案2
我不会尝试缩小方程的大小以使其适合一行,而是使用multline
环境并将方程排版为四行:三行表示分子,第四行即最后一行表示分母。请注意,在下面的解决方案中,我省去了\frac
符号。
\documentclass{article}
\usepackage{amsmath} % for 'multline' env.
\begin{document}
\begin{multline}\label{EEDIeq}
\Biggl\{\biggl(\,\prod_{j=1}^n f_j\biggr)
\biggl(\,\sum_{i=1}^{n_{\mathrm{\mathrm{ME}}}}
P_{\mathrm{\mathrm{ME}}(i)}\cdot
C_{\mathrm{FME}(i)}\cdot
\mathit{SFC}_{\mathrm{\mathrm{ME}}(i)}\biggr)
+ P_{\mathrm{AE}}\cdot C_{\mathrm{FAE}}
\cdot \mathit{SFC}_{\!\mathrm{AE}}\\
+ \biggl[\biggl(\,\prod_{j=1}^n f_j\cdot
\sum_{i=1}^{n_{\mathrm{PTI}}} P_{\mathrm{PTI}(i)}
-\sum_{i=1}^{n_{\mathrm{eff}}}f_{\mathrm{eff}(i)}\cdot
P_{\mathrm{AE}_{\mathrm{eff}}(i)}\biggr)
C_{\mathrm{FAE}}\cdot \mathit{SFC}_{\!\mathrm{AE}}\biggr] \\
-\biggl(\,\sum_{i=1}^{n_{\mathrm{eff}}}f_{\mathrm{eff}(i)}
\cdot P_{\mathrm{eff}(i)}\cdot C_{\mathrm{FME}}
\cdot \mathit{SFC}_{\mathrm{ME}}\biggr) \Biggr\}\\
\Big/\Bigl\{f_i\cdot f_c\cdot f_l\cdot \mathit{Capacity}
\cdot f_w\cdot V_{\mathrm{ref}}\Bigr\}
\end{multline}
\end{document}