在对齐环境内换行

Question

我在对齐环境中有一堆文本溢出到边距。我想将其换行。请注意，我使用的文档类与下面的状态不同。

\documentclass[11pt]{article}

\usepackage{amsmath}

\begin{document}

\begin{align}
    e_i &= \varepsilon(d_i, y_i) + \lambda\frac{1}{2} \vert w \vert ^2\label{eq:regularisation} \\
    \textnormal{where:} & \nonumber \\
    \varepsilon(\cdot) &= \textnormal{cost function} \nonumber \\
    w &= \textnormal{weights matrix of connection from immediate right layer (towards output layer)} \nonumber 
\end{align}


\end{document}

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我能想到的唯一解决方案是：

    w &= \textnormal{weights matrix of connection from immediate right} \nonumber \\
      &= \textnormal{layer (towards output layer)} \nonumber 

我希望有一个更好的解决方案，因为我不想每次句子长度改变时都要进行更改。

Answer 1

\documentclass[11pt]{article}

\usepackage{amsmath}

\begin{document}

\begin{align}
    e_i &= \varepsilon(d_i, y_i) + \lambda\frac{1}{2} \vert w \vert ^2\label{eq:regularisation} \\
    \textnormal{where:} & \nonumber \\
    \varepsilon(\cdot) &= \parbox[t]{5cm}{\raggedright cost function} \nonumber \\
    w &= \parbox[t]{5cm}{\raggedright weights matrix of connection from immediate right layer (towards output layer)} \nonumber 
\end{align}


\end{document}

Answer 2

您可以使用tabular环境来获得完全控制权，并且\shortintertext从mathtools：

\documentclass[11pt]{article}
\usepackage{mathtools}

\begin{document}

\begin{align}
    e_i &= \varepsilon(d_i, y_i) + \lambda\frac{1}{2} \vert w \vert ^2\label{eq:regularisation} \\
    \shortintertext{where:}
    \varepsilon(\cdot) &= \textnormal{cost function} \nonumber \\
    w &= \begin{tabular}[t]{@{}l@{}}weights matrix of connection from immediate right layer\\ (towards output layer)\end{tabular} \nonumber
\end{align}

\end{document}