# Nodes with cases in mathematics for tikZ

With thanks to this question, the accepted answer is quite clever:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{matrix,positioning}

\begin{document}

\begin{tikzpicture}[every left delimiter/.style={xshift=1ex}]
\node (r) {$\vec{r}=\vec{r}(\vec{R},t)$};
\matrix[matrix of math nodes,left delimiter=\lbrace,below = 10pt of r] (mat)
{
x_1 = F(x) \\
\cdots \\
x_1 = F(x) \\
};
\draw[->,shorten >= 6pt] (r.west) -- +(-15pt,0) |- (mat);
\end{tikzpicture}

\end{document}


I would like to add 'X=' to the left of the large brace. I don't need the arrow. How can I do this?

• Do you mean you don't need the line with arms, from r = to the brace? – Bernard Jan 2 '18 at 22:43

Like this?

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{matrix,positioning}

\begin{document}

\begin{tikzpicture}[every left delimiter/.style={xshift=1ex}]
\node (r) {$\vec{r}=\vec{r}(\vec{R},t)$};
\matrix[matrix of math nodes,left delimiter=\lbrace,below = 10pt of r] (mat)
{
x_1 = F(x) \\
\cdots \\
x_1 = F(x) \\
};
%\draw[->,shorten >= 6pt] (r.west) -- +(-15pt,0) |- (mat);

\node [left=5pt of mat,yshift=1pt] {$X=$};
\end{tikzpicture}

\end{document}


Why not a cases with an aligned environments? I also suggest vertical dots inside, rather than horizontal, and centred w.r.t. the left-hand side (\vdotswithin* command frommathtools), and the niver looking arrows fromesvect:

\documentclass{article}
\usepackage{mathtools}
\usepackage[b]{esvect}

\begin{document}

\begin{align*}
& \enspace \vv{r}=\vv{r}\bigl(\vv{R\,},t\bigr) \\
X = &
\begin{cases}
\begin{aligned}
x_1 & = F(x) \-1.5ex] \shortvdotswithin*{=} & \\[-2ex] x_1 & = F(x) \end{aligned} \end{cases} \end{align*} \end{document}  • (+1) I was about to put \vdots but it brings me some errors that I could not help. I did not know about \vdotswithin*. – Cragfelt Jan 3 '18 at 1:25 But since you are not needing the arrow, you can just wrap the equations into an array environment, with no TikZ involved \documentclass{article} \usepackage{amsmath} \begin{document} \[ \begin{array}{cc} & \quad\vec{r}=\vec{r}(\vec{R},t) \\[3ex] X = & \left\{ \begin{aligned} x_1 & = F(x) \\ & \cdots \\ x_1 & = F(x) \end{aligned} \right. \end{array}

\end{document}

• Have you heard of \begin{cases}...\end{cases}`? – Henri Menke Jan 3 '18 at 1:49
• @HenriMenke Yes, sure. But I decided to elaborate this one by considering other options. – Cragfelt Jan 3 '18 at 1:52