53

I know that \langle and \rangle creates left and right angle brackets. But they don't seem to adopt to the size of the expression inside. For example, if I have a big matrix, I would like to angle brackets to be big as well. How can I get this effect?

4
  • 2
    You can place \left and \right before each of them, respectively.
    – OSE
    Apr 14, 2013 at 23:48
  • 11
    as for all delimiters in TeX use \left\langle...\right\rangle They have a maximum size though they do not get arbitrarily big. Apr 14, 2013 at 23:49
  • 2
    \left< and \right> are abbreviations for \left\langle and \right\rangle, respectively. Apr 15, 2013 at 0:32
  • 2
    @AriBrodsky the point is that \left\right doesn't make delimiters big enough in this case, so \left< has same problem. Apr 15, 2013 at 0:36

4 Answers 4

26

The mtpro2 package (MathTime Professional II) provides extra-large (up to 10 cm tall) fence symbols -- round parentheses, square brackets, curly braces, angle brackets, etc. -- via its \LEFTRIGHT command. Note that the full mtpro2 package isn't free of charge; however, its "lite" subset, which is all that's needed to produce extra-large fence symbols, is free of charge.

enter image description here

\documentclass{article}
\usepackage[lite]{mtpro2}
\begin{document}
\[
\LEFTRIGHT\langle\rangle{
\begin{array}{c} 
  1\\2\\3\\4\\5\\6\\7\\8\\9\\10
\end{array}}
\]
\end{document}

update 2020-10-01: The pctex.com site noted in my answer no longer seems provide a functioning link to the page from which the lite subset of the mtpro2 package used to be available for downloading. Many thanks to @mateuszb for bringing this issue to my attention.


5
  • 4
    Usual comment about perennial enmity between the copy editor and the creator of such a horror. ;-)
    – egreg
    Apr 15, 2013 at 9:19
  • Sadly the link on the company's page to the LITE version does not work anymore.
    – mateuszb
    Sep 30, 2020 at 14:28
  • @mateuszb - Did their website maybe suffer an outage? I just checked pctex.com/mtpro2.html#Pricing. It still seems to be possible to click on the "FREE" link next to "MTPro2 Lite".
    – Mico
    Sep 30, 2020 at 17:04
  • @Mico, the "Free" link is dead I believe. Thanks
    – mateuszb
    Oct 1, 2020 at 18:01
  • 1
    @mateuszb - That's rather unfortunate. I'll edit my answer to put in a note that the website's link to the "lite" version of the font package appears to be dead.
    – Mico
    Oct 1, 2020 at 18:04
23

In the standard fonts \langle has a fixed upper limit and doesn't grow above a certain size. (TeX extends characters by adding vertical extension glyphs and angle brackets don't have a vertical section that can be extended). However if you don't mind distorting the shape you can scale the bracket to fit:

enter image description here

\documentclass{article}
\usepackage{amsmath}
\usepackage{graphicx}
\begin{document}

\[
\left\langle\begin{array}{c}1\\2\\3\\4\\5\\6\end{array}\right\rangle
\]

\[
\sbox0{$\begin{array}{c}1\\2\\3\\4\\5\\6\end{array}$}
\mathopen{\resizebox{1.2\width}{\ht0}{$\Bigg\langle$}}
\usebox{0}
\mathclose{\resizebox{1.2\width}{\ht0}{$\Bigg\rangle$}}
\]

\end{document}
2
  • The stretched angle brackets currently don't seem to be quite tall enough to "cover" the lower part of the bottom row. Is there an adjustment to achieve this coverage?
    – Mico
    Apr 15, 2013 at 10:27
  • @Mico you can change \ht0 to 1.1\ht0 or whatever factor you like You can also fiddle with \raisebox{...}{\usebox{0}} to adjust the position of the box within the delimiters (the more you scale the more the difference between centering on the baseline and centering on the math axis is apparent) Apr 15, 2013 at 11:24
11

This is the sort of thing the scalerel package was designed for. WIth the use of the width-limited \scaleleftright or aspect-limited \stretchleftright, a desirable outcome can often be achieved. In the below example, I show both, first employing \scaleleftright with a width limit of 1.75ex, and then showing \stretchleftright with an aspect limit of 1000% (i.e. stretch of 10). Note that in all cases, the symbols being manipulated are the humble < and > symbols, not some predefined stretchable version.

Finally, in the third figure set, I show that one can use a stretched version of \langle and \rangle, instead of < and >. Depending on the tastes of the user, one may be preferable to the other.

\documentclass{article}
\usepackage{scalerel}
\begin{document}

\setlength\arraycolsep{0ex}
\(
\scaleleftright{<}
{x}
{>}
%
\scaleleftright[1.75ex]{<}
{\begin{array}{c}x\\y\\z \end{array}}
{>}
%
\scaleleftright[1.75ex]{<}
{\begin{array}{c}u\\v\\w\\x\\y\\z \end{array}}
{>}
%
\scaleleftright[1.75ex]{<}
{\begin{array}{c}r\\s\\t\\u\\v\\w\\x\\y\\z \end{array}}
{>}
\)

\(
\stretchleftright{<}
{x}
{>}
%
\stretchleftright[1000]{<}
{\begin{array}{c}x\\y\\z \end{array}}
{>}
%
\stretchleftright[1000]{<}
{\begin{array}{c}u\\v\\w\\x\\y\\z \end{array}}
{>}
%
\stretchleftright[1000]{<}
{\begin{array}{c}r\\s\\t\\u\\v\\w\\x\\y\\z \end{array}}
{>}
\)

\(
\stretchleftright{\langle}
{x}
{\rangle}
%
\stretchleftright[1000]{\langle}
{\begin{array}{c}x\\y\\z \end{array}}
{\rangle}
%
\stretchleftright[1000]{\langle}
{\begin{array}{c}u\\v\\w\\x\\y\\z \end{array}}
{\rangle}
%
\stretchleftright[1000]{\langle}
{\begin{array}{c}r\\s\\t\\u\\v\\w\\x\\y\\z \end{array}}
{\rangle}
\)

\end{document}

enter image description here

enter image description here

enter image description here

1
  • I think this is the best way to do it out of all answers, but the example is quite long which is why I left it as the last thing to try!
    – mateuszb
    Sep 30, 2020 at 14:45
0

The nicest solution I can think of is using the braket package.

\documentclass[class=article,border=5pt]{standalone}
\usepackage{braket}

\begin{document}
$
\Braket{
    \begin{array}{lcl}
               z & =  a \\
                 & =  a \\
        f(x,y,z) & =  x + y + z
    \end{array}
}
$

$
\Braket{
    \begin{array}{lcl}
               z & =  \frac{a}{b} \\[2ex]
                 & =  \frac{a}{b} \\[2ex]
        f(x,y,z) & =  x + y + z
    \end{array}
}
$
\end{document}

to get right angle brackets which adjust to size. Unfortunately, like other solutions here the brackets do not stretch when the vertical line spacing is increased.

enter image description here

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