draw round/rectangular bracket embracing nodes in tikz

Question

I know how to draw a curly bracket with the following code:

\draw[decorate,decoration={brace,amplitude=5},-] (0.8,-0.75) -- (0.8,0.75);

But now I want to draw a round bracket, or a rectangular one. Can anyone tell how can I do this? Is it possible to do this by changing "brace" to some other values?

The result should look like: (some pictures)

but not {some pictures}

It would be helpful if you composed a fully compilable MWE including \documentclass and the appropriate packages that sets up the problem.
While solving problems can be fun, setting them up is not. Then, those trying to help can simply cut and paste your MWE and get started on solving the problem. — Peter Grill, Sep 30 '14 at 05:01

score 11 · Accepted Answer · edited Jun 10 '20 at 12:32

Below I define the styles

square left brace,
square right brace,
round left paren, and
round right paren

which yield:

enter image description here

Notes:

This is simply and adaptation of the ncbar style from Is there a TikZ equivalent to the PSTricks \ncbar command?.

Code:

\documentclass[landscape]{article}
\usepackage{tikz}
\usetikzlibrary{calc}
%% https://tex.stackexchange.com/questions/55068/is-there-a-tikz-equivalent-to-the-pstricks-ncbar-command
\tikzset{
    ncbar angle/.initial=90,
    ncbar/.style={
        to path=(\tikztostart)
        -- ($(\tikztostart)!#1!\pgfkeysvalueof{/tikz/ncbar angle}:(\tikztotarget)$)
        -- ($(\tikztotarget)!($(\tikztostart)!#1!\pgfkeysvalueof{/tikz/ncbar angle}:(\tikztotarget)$)!\pgfkeysvalueof{/tikz/ncbar angle}:(\tikztostart)$)
        -- (\tikztotarget)
    },
    ncbar/.default=0.5cm,
}
\tikzset{square left brace/.style={ncbar=0.5cm}}
\tikzset{square right brace/.style={ncbar=-0.5cm}}
\tikzset{round left paren/.style={ncbar=0.5cm,out=120,in=-120}}
\tikzset{round right paren/.style={ncbar=0.5cm,out=60,in=-60}}
\begin{document}
\begin{tikzpicture}
    \draw [red, thick] (0,0) to [square left brace ] (0,4);
    \draw [red, thick] (1,0) to [square right brace] (1,4);
\draw [blue, thick] (3,0) to [round left paren ] (3,4);
\draw [blue, thick] (4,0) to [round right paren] (4,4);

\end{tikzpicture}
\end{document}

Peter, how would one go about adapting this to draw horizontal braces over nodes? — Pedro, May 12 '18 at 14:14
See Curly brace to insert something into an equation? Like an inverted underbrace, or you should be able to adapt a solution for underbraces such as and How avoid that the Underbrace Outside the delimiters $| |$ appear inside the delimiters. If those don't solve your problem, please post a new question and include a fully compilable MWE that sets up the problem including the \documentclass and the appropriate packages. — Peter Grill, May 12 '18 at 21:22

score 10 · Answer 2 · edited Apr 13 '17 at 12:34

There is no equivalent to brace for parentheses and square brackets that is defined in the TikZ library decorations.pathreplacing, unfortunately.

It depends on what your use case is as to whether the following recommendation is a sensible one or not, but one possible way you might achieve something like what you want is to make use of the \vphantom trick and the fact that ( and [ are delimiters.

Here, I put \left( and \right) in their own nodes that are placed relative to the main node using the TikZ library positioning.

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{positioning}

\usepackage{graphicx}
\usepackage{mwe}

\begin{document}

\begin{tikzpicture}
    \node (picture) at (0,0) {\includegraphics[width=.5\textwidth]{image-a}};
    \node (left-paren) [left = of picture] {$\left(\vphantom{\includegraphics[width=.25\textwidth]{image-a}}\right.$};
    \node (right-paren) [right = of picture] {$\left.\vphantom{\includegraphics[width=.25\textwidth]{image-a}}\right)$};
\end{tikzpicture}

\end{document}

enter image description here

If you don't want to wrap an image in parantheses you can use \rule{width}{height} instead of \includegraphics... to set the desired height. I think this should be the accepted answer, because the other answer produces ugly parantheses for bigger heights. — MaPePeR, May 02 '16 at 11:18
I agree with @MaPePeR, great answer - please add their good suggestion as well. — kabanus, Mar 31 '19 at 10:14

draw round/rectangular bracket embracing nodes in tikz

2 Answers2

Notes:

Code:

Linked