Increasing the size of a symbol "|"
You can use \middle|
, and you have to add some horizontal spacing on the right and on the left.
Even if you don't want to use external package modules, I suggest using the DeclarePairedDelimiter
from mathtools
(which is just an extension of amsmath
, which takes care of all the spacing problems, and loading xparse
to simplify the syntax (both arguments are separated by a ;
). Here is a code for each solution:
\documentclass{article}
\usepackage{xparse, mathtools, amsfonts}
\DeclarePairedDelimiterX{\set}[1]\{\}{\setargs{#1}}
\NewDocumentCommand{\setargs}{>{\SplitArgument{1}{;}}m}
{\setargsaux#1}
\NewDocumentCommand{\setargsaux}{mm}
{\IfNoValueTF{#2}{#1}{\nonscript\,#1\nonscript\;\delimsize\vert\nonscript\:\allowbreak #2\nonscript\,}}
\begin{document}
\[ G=\left\{ \begin{pmatrix}t & 0\\
0 & \frac{1}{t}
\end{pmatrix}\,\middle|\, t\in\mathbb{R}^{\times}\right\} \]
\bigskip
\[ G=\set*{ \begin{pmatrix}t & 0\\
0 & \frac{1}{t}
\end{pmatrix} ; t\in\mathbb{R}^{\times}} \]
\end{document}
First off, I would use inline-fraction notation, 1/t
, instead of \frac{1}{t}
in order to typeset the matrix more compactly. If you're OK with using psmallmatrix
instead of pmatrix
, you can then get by with \bigl(
, \bigm|
(or \bigm\vert
), and \bigr)
. If you prefer using pmatrix
, use \biggl(
, \biggm|
, and \biggr)
instead.
Observe that \biggm|
automatically adds the typographically required amount of whitespace around the vertical bar. This is in contrast to \bigg|
, wwhere no whitespace is inserted.
\documentclass{article}
\usepackage{mathtools} % for 'psmallmatrix' env.
\usepackage{amssymb} % for '\mathbb' macro
\begin{document}
\begin{align*}
G&=\bigl\{
\begin{psmallmatrix} t & 0\\ 0 & 1/t \end{psmallmatrix}
\bigm|
t\in\mathbb{R}^{\times}
\bigr\} \\
&=\biggl\{
\begin{pmatrix} t & 0\\ 0 & 1/t \end{pmatrix}
\biggm|
t\in\mathbb{R}^{\times}
\biggr\}
\end{align*}
\end{document}
I don't think this is a Lyx-specific issue. Does this work for you?
\documentclass{article}
\usepackage{amsmath}
\begin{document}
$
G=\left\{
\left. %ADDED (as a blank bracket)
\begin{pmatrix}
t & 0\\
0 & \frac{1}{t}
\end{pmatrix}
\right| %ADDED (as expandable bracket)
t\in\mathbb{R}^{\times}\right\}
$
\end{document}
The way this works is be wrapping another set of brackets around the pmatrix
environment. The first one is empty (\left.
) while the you replace the current |
as the companion right bracket (\right|
). This allows it to match the height automatically.