# Vertical equivalent for \overbrace and \underbrace

Is there a way to label a vector like this in LaTeX? (like \overbrace/\underbrace but vertically)

a \
a  |
a   > Segment a
a  |
a /
b \
b  |
b   > Segment b
b  |
b /


I assume I can't be the first one that asks that, however I was not able to find anything helpful.

• Use \left. .... \right\}. Note the use of dot after \left. – Sigur Jul 21 '13 at 11:37

One way to do it:

\left.
\begin{array}{rrr}
a\\
a\\
a\\
a\\
a
\end{array}
\right\}\text{Segment a}


Output:

EDIT: I see, in your case, you will want to use bigdelim package, for example:

\documentclass{article}
\usepackage{multirow,bigdelim}

\begin{document}

$\begin{array}{cc} a&\rdelim\}{5}{1em}[Segment a]\\ a\\ a\\ a\\ a\\ b&\rdelim\}{5}{1em}[Segment b]\\ b\\ b\\ b\\ b\\ \end{array}$

\end{document}


will give you:

• i knew that possibility, but it is not quite what I am looking for, because I need to have more than one Segment. Maybe I just don't quite get what you mean, but if I see this correctly this only works for one segment. If I put the second segment below the first one I can't use the usual vector brackets, or else each array will be in its own bracket – kyra Jul 21 '13 at 11:52
• @kyra: updated. – Francis Jul 21 '13 at 12:12

Improving the @Francis's code, you can use two rows with two blocks.

$\begin{array}{r} \left. \begin{array}{r} a\\ a\\ a\\ a\\ a \end{array} \right\}\text{Segment a} \\ \left. \begin{array}{r} b\\ b\\ b\\ b\\ b \end{array} \right\}\text{Segment b} \end{array}$


Another way using the rcases environment from mathtools

\documentclass{article}
\usepackage{mathtools}

\begin{document}
\noindent
$\begin{rcases} a\\a\\a\\a\\a \end{rcases} \text{Segment A}$\\
$\begin{rcases} b\\b\\b\\b\\b \end{rcases} \text{Segment B}$
\end{document}