文档中特定方程块的左对齐

Question

我的论文中有大量方程式。我希望将下面给出的三个方程式的特定块对齐到页面左侧。我该怎么做？

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{equation}\label{C_row3}
\begin{split}
C31 = &-L_{1}\,d_{3}\,m_{3}\,\dot \theta_1\,\sin\left(\theta_1-\theta_3\right)\\
C35 =& 0
\end{split}
\end{equation}
\begin{equation}
\begin{split}
C41 =& -L_{1}\,\dot \theta_1\,\sin\left(\theta_1+\theta_4\right)\,\left(L_{4}\,m_{4}+L_{4}\,m_{5}-d_{4}\,m_{4}\right)\\
\end{split}
\end{equation}
\begin{equation}
\begin{split}
C_{51} = &{}-L_{1}\,m_{5}\,\dot \theta_1\,\sin\left(\theta_1+\theta_5\right)\,\left(L_{5}-d_{5}\right)\\
C_{55} =&{} 0
\end{split}
\end{equation}
\end{document}

Answer 1

环境fleqn，来自nccmath，就是为此而做的。它的工作原理或多或少类似于subequations。此外，您可以选择 的值\displayindent作为可选参数：

\documentclass{article}
\usepackage[showframe]{geometry}
\usepackage{nccmath}
\usepackage{amsmath}

\begin{document}

\begin{fleqn}
\begin{equation}\label{C_row3}
\begin{split}
C31 = &-L_{1}\,d_{3}\,m_{3}\,\dot \theta_1\,\sin\left(\theta_1-\theta_3\right)\\
C35 =& 0
\end{split}
\end{equation}
\begin{equation}
\begin{split}
C41 =& -L_{1}\,\dot \theta_1\,\sin\left(\theta_1+\theta_4\right)\,\left(L_{4}\,m_{4}+L_{4}\,m_{5}-d_{4}\,m_{4}\right)\\
\end{split}
\end{equation}
\begin{equation}
\begin{split}
C_{51} = &{}-L_{1}\,m_{5}\,\dot \theta_1\,\sin\left(\theta_1+\theta_5\right)\,\left(L_{5}-d_{5}\right)\\
C_{55} =&{} 0
\end{split}
\end{equation}
\end{fleqn}
\bigskip

\begin{fleqn}[1.5em]
\begin{equation}\label{C_row3}
\begin{split}
C31 = &-L_{1}\,d_{3}\,m_{3}\,\dot \theta_1\,\sin\left(\theta_1-\theta_3\right)\\
C35 =& 0
\end{split}
\end{equation}
\begin{equation}
\begin{split}
C41 =& -L_{1}\,\dot \theta_1\,\sin\left(\theta_1+\theta_4\right)\,\left(L_{4}\,m_{4}+L_{4}\,m_{5}-d_{4}\,m_{4}\right)\\
\end{split}
\end{equation}
\begin{equation}
\begin{split}
C_{51} = &{}-L_{1}\,m_{5}\,\dot \theta_1\,\sin\left(\theta_1+\theta_5\right)\,\left(L_{5}-d_{5}\right)\\
C_{55} =&{} 0
\end{split}
\end{equation}
\end{fleqn}

\end{document}

Answer 2

使用nccmath包，您可以使用fleqn环境来实现您想要的：

% Preamble
\usepackage{nccmath}

% Body
\begin{fleqn}
% Your equations in here
\end{fleqn}