align我有一个很长的方程式，我使用或将其分成几行split。不幸的是，在我的 pdf 文件中，这个方程式的一半在一页，其余部分在下一页，这就是方程式编号没有出现的原因，尽管方程式的顺序得以保留。此外，虽然它有一个标签，但我无法引用这个方程式。我怎样才能在方程式后面得到方程式编号？请注意，我必须使用\scriptstyle以使方程式适合页面宽度。
这是一个较小的例子：
\documentclass{article}
\usepackage{amsmath}
\begin{document}
{\scriptstyle
\begin{equation} \label{Model}
\begin{align}
\prod_{i=1}^{n}&\Biggl\{\Big[\sum_{k=1}^{2}\left(\frac{1}{\nu (\sum_{j=1}^{t-1}\exp(\rho(j)+\beta^TZ_i))+1}\right)^{1/\nu}-\left(\frac{1}{\nu (\sum_{j=1}^{t}\exp(\rho(j)+\beta^TZ_i))+1}\right)^{1/\nu}\pi_{\eta}^{(k)}(\varepsilon_i)\Big]^{1-\delta_i} \times \notag \\
&\Biggl[\left(\left(\frac{1}{\nu (\sum_{j=1}^{t-1}\exp(\rho(j)+\beta^TZ_i))+1}\right)^{1/\nu}-\left(\frac{1}{\nu (\sum_{j=1}^{t}\exp(\rho(j)+\beta^TZ_i))+1}\right)^{1/\nu}\pi_{\eta}^{(1)}(\varepsilon_i)\right)^{I_{(\varepsilon_i_i=1)}} \times \notag \\
&\left(\left(\frac{1}{\nu (\sum_{j=1}^{t-1}\exp(\rho(j)+\beta^TZ_i))+1}\right)^{1/\nu}-\left(\frac{1}{\nu (\sum_{j=1}^{t}\exp(\rho(j)+\beta^TZ_i))+1}\right)^{1/\nu}\pi_{\eta}^{(2)}(\varepsilon_i)\right)^{I_{(\varepsilon_i_i=2)}}\Biggr]^{\delta_i}.p_i\Biggr\}^{W_i\xi_i} \times \notag\\
&\Biggl\{\Big[\sum_{k=1}^{2}\left(\frac{1}{\nu (\sum_{j=1}^{t-1}\exp(\rho(j)+\phi^TZ_i))+1}\right)^{1/\nu}-\left(\frac{1}{\nu (\sum_{j=1}^{t}\exp(\rho(j)+\phi^TZ_i))+1}\right)^{1/\nu}\pi_{\eta}^{(k)}(\varepsilon_i)\Big]^{1-\delta_i} \times \notag \\
&\Biggl[\left(\left(\frac{1}{\nu (\sum_{j=1}^{t-1}\exp(\rho(j)+\phi^TZ_i))+1}\right)^{1/\nu}-\left(\frac{1}{\nu (\sum_{j=1}^{t}\exp(\rho(j)+\phi^TZ_i))+1}\right)^{1/\nu}\pi_{\eta}^{(1)}(\varepsilon_i)\right)^{I_{(\varepsilon_i_i=1)}} \times \notag \\
&\left(\left(\frac{1}{\nu (\sum_{j=1}^{t-1}\exp(\rho(j)+\phi^TZ_i))+1}\right)^{1/\nu}-\left(\frac{1}{\nu (\sum_{j=1}^{t}\exp(\rho(j)+\phi^TZ_i))+1}\right)^{1/\nu}\pi_{\eta}^{(2)}(\varepsilon_i)\right)^{I_{(\varepsilon_i_i=2)}}\Biggr]^{\delta_i}.(1-p_i)\Biggr\}^{W_i(1-\xi_i)}.
\end{align}
\end{equation}
}
\end{document}
答案1
不幸的是，内部的构建块（例如split或aligned（align不允许））equation不允许分页。相反，将其用作align唯一环境，并插入\notag以抑制不必要的编号。不要减小等式的大小，而是引入表示大型重复表达式的符号：
\documentclass{article}
\usepackage{amsmath}
\begin{document}
\mbox{}
\vspace{15cm}
{\allowdisplaybreaks
\begin{align} \label{Model}
\prod_{i=1}^{n}
&\biggl\{
\biggl[
\sum_{k=1}^{2}
x(\beta,i,t-1)-x(\beta,i,t)\pi_{\eta}^{(k)}(\varepsilon_i)
\biggr]^{1-\delta_i}
\notag \\
&\qquad \times
\Bigl[
\bigl(
x(\beta,i,t-1) - x(\beta,i,t)\pi_{\eta}^{(1)}(\varepsilon_i)
\bigr)^{I_{(\varepsilon_i=1)}}
\notag \\
&\hspace{4em} \times
\bigl(
x(\beta,i,t-1) -x(\beta,i,t)\pi_{\eta}^{(2)}(\varepsilon_i)
\bigr)^{I_{(\varepsilon_i=2)}}
\Bigr]^{\delta_i} \cdot p_i
\biggr\}^{W_i\xi_i} \notag \\
&\times
\biggl\{
\Bigl[
\sum_{k=1}^{2}
x(\phi,i,t-1) - x(\phi,i,t)\pi_{\eta}^{(k)}(\varepsilon_i)
\Bigr]^{1-\delta_i} \notag \\
&\qquad \times
\Bigl[
\bigl(
x(\phi,i,t-1)- x(\phi,i,t)\pi_{\eta}^{(1)}(\varepsilon_i)
\bigr)^{I_{(\varepsilon_i=1)}} \notag \\
&\hspace{4em} \times
\bigl(
x(\phi,i,t-1)-x(\phi,i,t)\pi_{\eta}^{(2)}(\varepsilon_i)
\bigr)^{I_{(\varepsilon_i=2)}}
\Bigr]^{\delta_i} \cdot (1-p_i)
\biggr\}^{W_i(1-\xi_i)},
\label{Model}
\end{align}
}
where \( x(A,i,t) = (\nu(\sum_{j=1}^{t} \exp(\rho(j)+A^{T}Z_{i}))+1)^{-1/\nu} \)
\end{document}