Math & Science ⇒ number of the equation below the formula

[NELLLY]

Hello
I have a miltiline formula. To get the equation number only for the last equation I used the following code

Code: Select all

\documentclass[12pt]{article}

\renewcommand{\baselinestretch}{1.5}
\date{}

\usepackage{pdfpages}

\usepackage{tabularx,graphicx,rotating,subfigure,multirow}
\usepackage{booktabs}
 \usepackage{array}
 \usepackage{siunitx,amsmath}
 \usepackage[T1]{fontenc}

\usepackage{multirow}
\usepackage{mathtools}

\usepackage[format=hang]{caption}

\hyphenpenalty 100000
\usepackage{authblk}
\date{}

\usepackage{geometry}
\geometry{
  text={6in,8.9in},
  headsep=.4in,
  footnotesep=.2in
}
\captionsetup{
  format=hang,
  width=17cm,
  aboveskip=4pt,
  belowskip=12pt
}
\begin{document}

\begin{align}
\begin{split}
P(S_0=x, D_{S_0}\in I_1)&= \sum_{y=0}^{x-1} P\left( \mbox{there are $y$ intervals of
length $h_1$ and $(x-1-y)$ intervals of length}\right.\\
&\mbox{$h_2$ between samples $1$ and $x$, $D_x \in I_1$
and}\\
 &\left.h_2 (x-y)+y h_1 <T_A <h_2(x-y)+h_1 (y + 1)\right)\nonumber
 \end{split}\\
 &=\sum_{y=0}^{x-1}C_{y}^{x-1} p_{h_1}^{y} (1-p_{h{1}})^{x-1-y}\, p_{h_1} \int_{h_2 (x-y) +h_1 y}^{h_2 (x-y)+ h_1 (y+1)} \lambda  e^{-\lambda t} dt \;\;\mbox{for $x \geq 1$.}
\end{align}
\end{document}

but I get the number below the line of the equation. What should I do?
Thanks.

[Johannes_B]

I like loading package showframe in my minimal
working example, because that way i can see the margins of the
page a much better. Doing this in you case, immedeatly shows,
that your stuff is just too wide for the text block. There is an
according warning message in the log files ass well:

Code: Select all

Overfull \hbox (68.53334pt too wide) in paragraph at lines 49--49

I don't know what maths you have there, but i suggest to write
big/long equations on their own (displayed math). Simple maths
can be set in line.

Please note, that mbox creates a box, where hyphenation and line
breaking is prevented.

Code: Select all

\documentclass[12pt]{article}

\renewcommand{\baselinestretch}{1.5}
\usepackage{showframe}
\usepackage[T1]{fontenc}
\usepackage{mathtools}
\usepackage{physics}

\usepackage{geometry}
\geometry{
text={6in,8.9in},
headsep=.4in,
footnotesep=.2in
}
\begin{document}

\[P(S_0=x, D_{S_0}\in I_1)= \sum_{y=0}^{x-1} P\] 
there are $y$ intervals of 
length $h_1$ and $(x-1-y)$ intervals of length
$h_2$ between samples $1$ and $x$, $D_x \in I_1$ and
\begin{align*}
&\left.h_2 (x-y)+y h_1 <T_A <h_2(x-y)+h_1 (y + 1)\right)\\
&=\sum_{y=0}^{x-1}C_{y}^{x-1} p_{h_1}^{y} (1-p_{h{1}})^{x-1-y}\, p_{h_1} 
\int_{h_2 (x-y) +h_1 y}^{h_2 (x-y)+ h_1 (y+1)} \lambda
e^{-\lambda t}%
\dd{t}%coming from package physics
\;\;\mbox{for $x \geq 1$.}
\end{align*}
\bigskip


\begin{align}
\begin{split}
P(S_0=x, D_{S_0}\in I_1)&= \sum_{y=0}^{x-1} P\left( \mbox{there are $y$ intervals of
length $h_1$ and $(x-1-y)$ intervals of length}\right.\\
&\mbox{$h_2$ between samples $1$ and $x$, $D_x \in I_1$ and}\\
&\left.h_2 (x-y)+y h_1 <T_A <h_2(x-y)+h_1 (y + 1)\right)\nonumber
\end{split}\\
&=\sum_{y=0}^{x-1}C_{y}^{x-1} p_{h_1}^{y} (1-p_{h{1}})^{x-1-y}\, p_{h_1} \int_{h_2 (x-y) +h_1 y}^{h_2 (x-y)+ h_1 (y+1)} \lambda e^{-\lambda t} dt \;\;\mbox{for $x \geq 1$.}
\end{align}

\end{document}