Family Tree gone "wrong"

Question

Trying to make a simple tree, but when I finished I realized I'd gone about it totally the wrong way... Would appreciate some help trying to make this the "correct" way. Oh, and also to circle the last 5/3

\documentclass[12pt,a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage[swedish]{babel}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsthm}
\usepackage{tikz}
\usetikzlibrary{matrix}
\usetikzlibrary{calc,trees,positioning,arrows,fit,shapes,decorations.markings}

\begin{document}
\begin{tikzpicture}
\matrix(m)[matrix of math nodes,column sep=0.5cm,row sep=0.3cm,]{
     & & & \dfrac{1}{1} & & & \\
     & \dfrac{1}{2} & & & & \dfrac{2}{1} & \\
     \dfrac{1}{3} & & \dfrac{3}{2} & & \dfrac{2}{3} & & \dfrac{3}{1} \\
     \vdots & & \vdots & & & \dfrac{5}{3} & \vdots \\
     };
\draw[->]
(m-1-4)edge(m-2-2)
(m-1-4)edge(m-2-6)
(m-2-2)edge(m-3-1)
(m-2-2)edge(m-3-3)
(m-2-6)edge(m-3-5)
(m-2-6)edge(m-3-7)
(m-3-5)edge(m-4-6);
\end{tikzpicture}
\end{document}

enter image description here

You could have a look at the "Making trees grow" section of the TikZ manual. There is a child path action which is better suited to construct trees than using \matrix + edges. — Bordaigorl, May 19 '15 at 09:26
For a second, I thought you were from West Virginia (this is an attempt at American regional humor). — Steven B. Segletes, May 19 '15 at 10:20

score 2 · Accepted Answer · answered May 20 '15 at 07:57

With forest it's easy to change how the tree grows. It has a reversed option.

\documentclass{standalone}
\usepackage{forest}
\usepackage{amsmath}
\usepackage{etex}

\begin{document}
\begin{forest}
for tree={edge = ->, reversed}
[$\dfrac{1}{1}$
    [$\dfrac{1}{2}$
        [$\dfrac{1}{3}$[\vdots]]
        [$\dfrac{3}{2}$[\vdots]]]
    [$\dfrac{2}{1}$
        [$\dfrac{2}{3}$[,phantom][$\dfrac{5}{3}$, draw, circle]]
        [$\dfrac{3}{1}$[\vdots]]]]
\end{forest}
\end{document}

enter image description here

Family Tree gone "wrong"

1 Answers1