我有一个巨大的分数,页面放不下。我搜索了这个论坛,只找到了\begin{split}
、 或align*
等,但我认为这些不是我想要的。他们在符号处拆分方程,但在我的例子中,分数的分子和分母都有足够的元素,以至于页面放不下。(我无法再简化它了)
任何帮助,将不胜感激。
\documentclass[12]{article}
\usepackage{bm}
\usepackage{amsmath}
\usepackage{amsfonts}
$ \Leftrightarrow \theta_{0|t+1}\approx \frac{\displaystyle(\beta+1)\frac{P(y|\Theta_{t+1})}{P(y|\Theta_{t})}\sum_{s \in S}P(s|y;\Theta_{t+1})\sum_{k=1}^T(y_k- \phi_{1|t+1}(s_k))y_{k-1}+(1-\beta)\sum_{s \in S}P(s|y;\Theta_{t+1})\sum_{k=1}^T(y_k- \phi_{1|t+1}(s_k))y_{k-1}}{\displaystyle(\beta+1)\frac{P(y|\Theta_{t+1})}{P(y|\Theta_{t})}\sum_{s \in S} P(s|y;\Theta_{t+1})\sum_{k=1}^T ( \phi_{0|t+1}(s_k)+y_{k-1})y_{k-1}+(1-\beta)\sum_{s \in S}P(s|y;\Theta_{t+1})\sum_{k=1}^T ( \phi_{0|t+1}(s_k)+y_{k-1})y_{k-1}} $
答案1
如果你真的想让你的读者接受这样一个可怕的公式,我认为除了分裂分子和分母之外没有别的方法了:
\documentclass{article}
\usepackage{mathtools}
\begin{document}
\[
\theta_{0|t+1}\approx
\frac{
\begin{multlined}
(\beta+1)\frac{P(y|\Theta_{t+1})}{P(y|\Theta_{t})}
\sum_{s \in S}P(s|y;\Theta_{t+1})\sum_{k=1}^T(y_k- \phi_{1|t+1}(s_k))y_{k-1}+{} \\
(1-\beta)\sum_{s \in S}P(s|y;\Theta_{t+1})
\sum_{k=1}^T(y_k- \phi_{1|t+1}(s_k))y_{k-1}
\end{multlined}
}{
\begin{multlined}
(\beta+1)\frac{P(y|\Theta_{t+1})}{P(y|\Theta_{t})}
\sum_{s \in S} P(s|y;\Theta_{t+1})\sum_{k=1}^T ( \phi_{0|t+1}(s_k)+y_{k-1})y_{k-1}+{}\\
(1-\beta)\sum_{s \in S}P(s|y;\Theta_{t+1})\sum_{k=1}^T
( \phi_{0|t+1}(s_k)+y_{k-1})y_{k-1}
\end{multlined}
}
\]
\end{document}
但为这四个部分定义缩写肯定会好得多;比如
\[
\theta_{0|t+1}\approx\frac{A(t)+B(t)}{C(t)+D(t)}
\]
where
\begin{align*}
A(t) &= (\beta+1)\frac{P(y|\Theta_{t+1})}{P(y|\Theta_{t})}
\sum_{s \in S}P(s|y;\Theta_{t+1})\sum_{k=1}^T(y_k- \phi_{1|t+1}(s_k))y_{k-1} \\
B(t) &= (1-\beta)\sum_{s \in S}P(s|y;\Theta_{t+1})
\sum_{k=1}^T(y_k- \phi_{1|t+1}(s_k))y_{k-1} \\
C(t) &= (\beta+1)\frac{P(y|\Theta_{t+1})}{P(y|\Theta_{t})}
\sum_{s \in S} P(s|y;\Theta_{t+1})\sum_{k=1}^T ( \phi_{0|t+1}(s_k)+y_{k-1})y_{k-1} \\
D(t) &= (1-\beta)\sum_{s \in S}P(s|y;\Theta_{t+1})\sum_{k=1}^T
( \phi_{0|t+1}(s_k)+y_{k-1})y_{k-1}
\end{align*}
答案2
以下是我的做法:
\documentclass{article}
\usepackage{amsmath}
\begin{document}
\noindent Let
\begin{align*}
A &= \frac{P(y \mid \Theta_{t + 1})}{P(y \mid \Theta_{t})},\\
B &= \sum_{s \in S} P(s \mid y; \Theta_{t + 1}),\\
C &= \sum_{k = 1}^{T} (y_{k} - \phi_{1 \mid t + 1}(s_{k}))y_{k - 1},\\
D &= \sum_{k = 1}^{T} (\phi_{0 \mid t + 1}(s_{k}) + y_{k - 1})y_{k - 1}.
\end{align*}
Then
\begin{equation*}
\theta_{0 \mid t + 1}
\approx \frac{(1 + \beta)ABC + (1 - \beta)BC}{(1 + \beta)ABD + (1 - \beta)BD}.
\end{equation*}
\end{document}