对齐 - 如何分别对齐方程组？

Question

如何才能在不引入额外垂直空间的情况下将两行方程分开对齐？例如，下面的代码给出了以下内容

\documentclass[twocolumn]{article}
\usepackage{amsmath}

\begin{document}

\begin{alignat}{4}
    \hat{y}_{\Psi}^t &= \Psi(h^t_\text{h}) + \hat{y}^{t-1} \hspace{-\textwidth} \\
    \hat{y}^t_{\Phi,s,i} &= \Phi([\hat{y}_{\Psi}^t \odot m,x_i^t,\mathrm{BPS}_i,s])\hspace{-\textwidth} \label{eq:doublegrabnets} \\
    \hat{y}^{'t} &= \hat{y}_{\Psi}^t\odot m_l &&+ \textstyle\sum_{i} \hat{\alpha}^t_{l,i}\hat{y}^t_{\Phi,l,i} &&\odot m_l + \hat{\alpha}^t_{l,\text{h}}\hat{y}_{\Psi}^t &&\odot m_l \label{eq:larmupdate} \\
    \hat{y}^t &= \hat{y}^{'t} \odot m_r &&+ \textstyle\sum_{i} \hat{\alpha}^t_{r,i}\hat{y}^t_{\Phi,r,i} &&\odot m_r + \hat{\alpha}^t_{r,\text{h}}\hat{y}^{'t} &&\odot m_r \label{eq:rarmupdate}
\end{alignat}
    
\end{document}

我想要这样的东西，但没有方程式 1,2 和 3,4 之间的额外间距。

Answer 1

从您展示的图像来看，我很确定您正在使用IEEEtran。

在展示我的解决方案之前，请注意

\hat{y}^{'t}

是错误的，应该是\hat{y}'^{t}（查看图像并与您的输出进行比较）。也\text{h}应该是\mathrm{h}。我提供了一种更好的方法来输入较小的\sum符号。

现在提出建议。

\documentclass{IEEEtran}
\usepackage{amsmath}

\usepackage{lipsum}% for context

\newcommand{\tsum}{\mathop{\textstyle\sum}\nolimits}

\newenvironment{multiplealignment}{%
  $$\vbox\bgroup
  \setlength{\abovedisplayskip}{\jot}%
  \setlength{\belowdisplayskip}{0pt}%
  \vspace{-\jot}%
}{\egroup$$}

\begin{document}

\lipsum[1][1-3]
\begin{multiplealignment}
\begin{align}
  \hat{y}_{\Psi}^t &= \Psi(h^t_{\mathrm{h}}) + \hat{y}^{t-1}
\\
  \hat{y}^t_{\Phi,s,i} &= \Phi([\hat{y}_{\Psi}^t \odot mx_i^t,\mathrm{BPS}_i,s])
    \label{eq:doublegrabnets}
\end{align}
\begin{alignat}{5}
  \hat{y}'^{t} &= \hat{y}_{\Psi}^t\odot m_l
              &&+ \tsum_{i} \hat{\alpha}^t_{l,i}\hat{y}^t_{\Phi,l,i} &&\odot m_l 
              &&+ \hat{\alpha}^t_{l,\mathrm{h}}\hat{y}_{\Psi}^t &&\odot m_l
    \label{eq:larmupdate}
\\
  \hat{y}^t &= \hat{y}'^{t} \odot m_r
           &&+ \tsum_{i} \hat{\alpha}^t_{r,i}\hat{y}^t_{\Phi,r,i} &&\odot m_r
           &&+ \hat{\alpha}^t_{r,\mathrm{h}}\hat{y}'^{t} &&\odot m_r
    \label{eq:rarmupdate}
\end{alignat}
\end{multiplealignment}
\lipsum[2][1-3]
    
\end{document}

Answer 2

我建议创建一个align环境alignat，并用合适的\vspace*指令将其分隔开。

\documentclass{article}
\usepackage[twocolumn,margin=2cm]{geometry}
\usepackage{amsmath}

\begin{document}

\begin{align}
\hat{y}_{\Psi}^t 
  &= \Psi(h^t_\mathrm{h}) + \hat{y}^{t-1}  \\
\hat{y}^t_{\Phi,s,i} 
  &= \Phi([\hat{y}_{\Psi}^t \odot m, x_i^t, \mathrm{BPS}_i, s]) 
  \label{eq:doublegrabnets}
\end{align}
\vspace*{-2.5\abovedisplayskip} % or '-2.75\abovedisplayskip'
\begin{alignat}{3}
\hat{y}'^{t} 
     &= \textstyle \hat{y}_{\Psi}^t\odot m_l 
     &&+\textstyle \sum_{i} \hat{\alpha}^t_{l,i}\hat{y}^t_{\Phi,l,i} \odot m_l 
     &&+\textstyle \hat{\alpha}^t_{l,\mathrm{h}}\hat{y}_{\Psi}^t \odot m_l 
  \label{eq:larmupdate} \\
\hat{y}^t 
     &= \textstyle \hat{y}'^{t} \odot m_r 
     &&+\textstyle \sum_{i} \hat{\alpha}^t_{r,i}\hat{y}^t_{\Phi,r,i} \odot m_r 
     &&+\textstyle \hat{\alpha}^t_{r,\mathrm{h}}\hat{y}'^{t} \odot m_r 
  \label{eq:rarmupdate}
\end{alignat}

\end{document}