方程式占用太多空间

Question

我有这组方程式，它们占用了太多空间。

有哪些建议可以使它们更加紧凑？

\begin{equation}
b_s(t) = \bm{p}_s \exp \left(-t \bm{B}_s\right)\bm{B}_s \bm{e}_s',
\end{equation}
where 
\begin{equation}
\bm{B}_s =  (\bm{B}_1 \oplus \bm{R}_2) - \lambda_R \bm{e}'( \bm{p}_1     
\otimes \bm{r}_2),
\end{equation}
\begin{displaymath}
\bm{p}_s = (1 - \rho_s)(\bm{p}_1 \otimes \bm{r}_2)\bm{K},
\end{displaymath}
\begin{displaymath}
\rho_s = \lambda_R ( \bm{p}_1 \otimes \bm{r}_2) (\bm{B}_1 \oplus    
\bm{R}_2)^{-1} \bm{e}_s',
\end{displaymath}
\begin{displaymath}
\bm{K}_s = (\bm{I} - \bm{U}_s)^{-1},\ \ \ \bm{U}_s = \bm{A}_s^{-1},
\end{displaymath}
\begin{displaymath}
\bm{A}_s = \bm{I} + \frac{1}{\lambda_R}( \bm{B}_1 \oplus \bm{R}_2) -    
\bm{e}' ( \bm{p}_1 \otimes \bm{r}_2 ),
\end{displaymath}
\begin{displaymath}
\bm{R}_2 = \bm{B}_2 - \lambda_A\bm{Q}_2,
\end{displaymath}
 \begin{displaymath}
 \bm{r}_2 = (1 - \rho_2)\lambda_A \bm{p}_2\bm{K}_2,\ 
\end{displaymath}
\begin{displaymath}
\rho_2 = \lambda_A \bm{p}_2 \bm{V}_2 \bm{e}_2,
\end{displaymath}
\begin{displaymath}
\bm{K}_2 = (\bm{I} - \bm{U}_2)^{-1},\ \ \ \bm{U}_2 = \bm{A}_2^{-1},
\end{displaymath}
\begin{displaymath}
\bm{A}_2 = \bm{I} + \frac{1}{\lambda_A}\bm{B}_2 -  \bm{e}_2' \bm{p}_2.
\end{displaymath}

更新：

好的。所以我使用了“gather”命令，看起来好多了。但仍然有空格。见下文...

Answer 1

默认情况下，方程式（和 displaymath）环境会在上方和下方留出一些空间。由于您已连续使用其中许多，因此它们会累加。您应该使用 align 环境来避免获得过多的间距。

下次，请发布完整可编译的代码，以便帮助其他人。

\documentclass[11pt]{article}
%
\usepackage{mathtools} 
\usepackage{esvect} 
\usepackage{amssymb}
\usepackage{bm}

\begin{document}

\begin{align}
b_s(t) &= \bm{p}_s \exp \left(-t \bm{B}_s\right)\bm{B}_s \bm{e}_s', \\
\shortintertext{where}
\bm{B}_s &=  (\bm{B}_1 \oplus \bm{R}_2) - \lambda_R \bm{e}'( \bm{p}_1     
\otimes \bm{r}_2), \\
\bm{p}_s &= (1 - \rho_s)(\bm{p}_1 \otimes \bm{r}_2)\bm{K}, \notag \\
\rho_s &= \lambda_R ( \bm{p}_1 \otimes \bm{r}_2) (\bm{B}_1 \oplus    
\bm{R}_2)^{-1} \bm{e}_s', \notag \\
\bm{K}_s &= (\bm{I} - \bm{U}_s)^{-1},\ \ \ \bm{U}_s = \bm{A}_s^{-1},
\notag \\
\bm{A}_s &= \bm{I} + \frac{1}{\lambda_R}( \bm{B}_1 \oplus \bm{R}_2) -    
\bm{e}' ( \bm{p}_1 \otimes \bm{r}_2 ), \notag \\
\bm{R}_2 &= \bm{B}_2 - \lambda_A\bm{Q}_2, \notag \\
 \bm{r}_2 &= (1 - \rho_2)\lambda_A \bm{p}_2\bm{K}_2,\  \notag \\
\rho_2 &= \lambda_A \bm{p}_2 \bm{V}_2 \bm{e}_2, \notag \\
\bm{K}_2 &= (\bm{I} - \bm{U}_2)^{-1},\ \ \ \bm{U}_2 = \bm{A}_2^{-1},
\notag \\
\bm{A}_2 &= \bm{I} + \frac{1}{\lambda_A}\bm{B}_2 -  \bm{e}_2'
\bm{p}_2.\notag 
\end{align}

\end{document}

输出：