Aligned equations inside of TikZ node.

Question

How can I create a tree node with an aligned math equations inside?

\begin{align}
\end{align}

doesn't work

\begin{minipage}{100}
  \begin{align}
    ...
  \end{align}
\end{minipage}

Gives a lot of margin and I don't want to manually tune 100.

\nodepart from shapes tikz library seems to be overkill and doesnt do the alignment.

Any ideas?

Answer 1

You could use an aligned environment with inline math inside nodes, their size is automatically calculated. Here's a small example with such a node in a tree:

\documentclass{article}
\usepackage{tikz}
\usepackage{amsmath}
\begin{document}
\begin{tikzpicture}[every node/.style={rectangle,draw}]
\node {Example:}
  child {node {%
  $\begin{aligned}
     a &= bx + c\\
     a+b &= d +1
  \end{aligned}$}};
\end{tikzpicture}
\end{document}

Output: