# How to affect the position of equation labels when using “aligned” environments inside an “align” environment

\begin{align}\label{abc}
&f(x,y,z) = \begin{aligned}[t]
& aaaaaaaaaaaaaaaaaaaaaaaaaaa\\
& + aaaaaaaaaaaaaaaaaaaaaaaaaaa\\
& - aaaaaaaaaaaaaaaaaaaaaaaaaaa,
\end{aligned}\\\label{abcd}
&g(x,y,z,w) = \begin{aligned}[t]
& aaaaaaaaaaaaaaaaaaaaaaaaaaa\\
& + aaaaaaaaaaaaaaaaaaaaaaaaaaa\\
& - aaaaaaaaaaaaaaaaaaaaaaaaaaa,
\end{aligned}
\end{align}
\eqref{abc} \eqref{abcd}


I want to change the position of (15) and (16) to where I want.

Is there any options like [t], [c], [b]?

The options [t] that I think imply that (15) is located the first line like the above figure.

The options [c] that I think imply that (15) is located the second line like the following figure.

The options [b] that I think imply that (15) is located the third line like the following figure.

• Can you elaborate Where I want here? – subham soni Dec 6 '17 at 5:37
• I've just added figures that I want. The figures are not from the LaTex. They are from the mspaint program. (I drew it.) – Danny_Kim Dec 6 '17 at 5:47
• the positioning options for aligned are meant to position the aligned block itself relative to what it follows, not the position of the label. – barbara beeton Dec 6 '17 at 17:57

## 2 Answers

To influence the vertical position of the equation label associated with a given aligned environment, you mainly need to reorganize some of the material.

For instance, in order to achieve top-alignment of the equation number, don't write

\label{abc}
&f(x,y,z) = \begin{aligned}[t]
& aaaaaaaaaaaaaaaaaaaaaaaaaaa\\
& + aaaaaaaaaaaaaaaaaaaaaaaaaaa\\
& - aaaaaaaaaaaaaaaaaaaaaaaaaaa,
\end{aligned}\\


Instead, you need to write

&\begin{aligned}[t] \label{abc}
f(x,y,z)   &= aaaaaaaaaaaaaaaaaaaaaaaaaaa\\
&\quad+ aaaaaaaaaaaaaaaaaaaaaaaaaaa\\
&\quad- aaaaaaaaaaaaaaaaaaaaaaaaaaa,
\end{aligned}\\


The single most important change is the placement of \begin{aligned}[t]: instead of coming after f(x,y,z), it has to come before it.

By the way, the only real placement options are [t] and [b] (for top and bottom); any other letter, including (but not limited to) [c], is ignored, resulting in the default placement, which is centered.

Here's a full MWE (minimum working example) which places the equation labels on the bottom rows:

\documentclass{article}
\usepackage{amsmath,newtxtext,newtxmath}
\usepackage[colorlinks,linkcolor=blue]{hyperref} % just for this example
\begin{document}
\setcounter{equation}{14} % just for this example

\begin{align}
&\begin{aligned}[b] \label{abc}
f(x,y,z)   &= aaaaaaaaaaaaaaaaaaaaaaaaaaa\\
&\quad+ aaaaaaaaaaaaaaaaaaaaaaaaaaa\\
&\quad- aaaaaaaaaaaaaaaaaaaaaaaaaaa,
\end{aligned}\\[1ex] % some extra whitespace, for "visual grouping"
&\begin{aligned}[b] \label{abcd}
g(x,y,z,w) &= aaaaaaaaaaaaaaaaaaaaaaaaaaa\\
&\quad + aaaaaaaaaaaaaaaaaaaaaaaaaaa\\
&\quad - aaaaaaaaaaaaaaaaaaaaaaaaaaa,
\end{aligned}
\end{align}

\eqref{abc}, \eqref{abcd}
\end{document}

• I should have pondered more!.. I just thought that there exist some options or new environments that I do not know yet. However, what I want can be done with only align and aligned environments. Very thank you~ – Danny_Kim Dec 6 '17 at 6:26

It's far more convenient to use align as-is with appropriately placed \nonumber (or \notag):

\documentclass{article}

\usepackage{amsmath}

\begin{document}

\begin{align}
f(x,y,z)
&=  aaaaaaaaaaaaaaaaaaaaaaaaaaa \nonumber \\
&\qquad {}+ aaaaaaaaaaaaaaaaaaaaaaaaaaa \nonumber \\
&\qquad {}- aaaaaaaaaaaaaaaaaaaaaaaaaaa, \label{eqn:abc} \\
g(x,y,z,w)
&=  aaaaaaaaaaaaaaaaaaaaaaaaaaa \nonumber \\
&\qquad {}+ aaaaaaaaaaaaaaaaaaaaaaaaaaa \nonumber \\
&\qquad {}- aaaaaaaaaaaaaaaaaaaaaaaaaaa, \label{eqn:abcd}
\end{align}
See equations~\eqref{eqn:abc} and~\eqref{eqn:abcd}.

\end{document}


While the alignment above is different from what you've supplied, that can be changed.