tree.tex (Source)

\documentclass{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}[xscale=2,yscale=0.5]
  \node (root) {all};
  \node at (1,2) (D) {$D$};
  \node at (1,-2) (nD) {${\sim}D$};
  \node at (2,3) (DY) {$Y$};
  \node at (2,1) (DN) {$N$};
  \node at (2,-1) (nDY) {$Y$};
  \node at (2,-3) (nDN) {$N$};
  \draw [->] (root) -- (D) node[at end, above left]{0.01};
  \draw [->] (root) -- (nD) node[at end, below left]{0.99};
  \draw [->] (D) -- (DY) node[at end, above left]{0.95};
  \draw [->] (D) -- (DN) node[at end, below left]{0.05};
  \draw [->] (nD) -- (nDY) node[at end, above left]{0.05};
  \draw [->] (nD) -- (nDN) node[at end, below left]{0.95};
\end{tikzpicture}
\end{document}