website/content/blog/drawing-trees-with-tikz-latex.md

---
title: "Drawing Trees in LaTex with Tikz"
date: 2022-12-06T11:01:24-05:00
draft: false 
tags: ["LaTex"]
math: false
---

For the longest time I've been avoiding Tikz because I imagined it being too difficult to learn. Usually I create a graphic using a program like [Draw.IO](https://draw.io) and import it as an image. Though this time around, I decided that I'm going to learn how to make trees in Tikz. It turns out, it's not as bad as I anticipated.

I'm only going to provide a few simple examples in this post. To learn more check out the [Tikz documentation on trees](https://tikz.dev/tikz-trees).

Remember to have `\usepackage{tikz}` in the preamble.

To create a Tikz figure, you'll need to create a `tikzpicture` environment

```latex
\begin{tikzpicture}
 % Tikz Code Here
\end{tikzpicture}
```

Every tree first begins with a root node.

```latex
\begin{tikzpicture}
	\node {Root Node};
\end{tikzpicture}
```

The semicolon at the end denotes the end of a `tikz` command.

Now let's make the root node have one child node.

```latex
\begin{tikzpicture}
	\node {Root Node}
		child {node {Child Node}};
\end{tikzpicture}
```

![Screenshot of tree with one node on each level](/files/images/blog/20221206111634.png)                   

Notice that the text of the nodes are within the `{}` after the node command.

To create another child for a node, place it in the same level as the existing child.

```latex
\begin{tikzpicture}
	\node {Root Node}
		child {node {Left Child}}
		child {node {Right Child}};
\end{tikzpicture}
```

![Screenshot of tree with the root node having two child nodes](/files/images/blog/20221206111922.png)

The rendered tree may have text overlap as shown in the last screenshot. This is where `tikz` options come in. We can define the separation distance between siblings. I don't have many tips for choosing the value other than to play around and see how it looks.

```latex
\begin{tikzpicture}
[
    level 1/.style={sibling distance=25mm}
]
	\node {Root Node}
		child {node {Left Child}}
		child {node {Right Child}};
\end{tikzpicture}
```

![Improved screenshot of previous tree but with well separated child nodes](/files/images/blog/20221206112150.png)

To show how the child nesting works, I'll finish by giving the right child two children nodes.

```latex
\begin{tikzpicture}
[
    level 1/.style={sibling distance=25mm},
    level 2/.style={sibling distance=15mm},
]
	\node {Root Node}
		child {node {Left Child}}
		child {
		    node {Right Child}
		    child {node {Child A}}
		    child {node {Child B}}
		};
\end{tikzpicture}
```

![Screenshot of a tree similar to the previous tree, but with the right child having two child nodes one with the label A and the other with the label B.](/files/images/blog/20221206112444.png)