Hierarchical Clustering Dendrogram in Latex

dendrogram.tex

\begin{tikzpicture}[sloped]
\node (a) at (-6,0) {a};
\node (b) at (-3,0) {b};
\node (c) at (-0.5,0) {c};
\node (d) at (0.5,0) {d};
\node (e) at (2,0) {e};
\node (ab) at (-4.5,3) {};
\node (cd) at (0,1) {};
\node (cde) at (1,2) {};
\node (all) at (-1.5,5) {};

\draw  (a) |- (ab.center);
\draw  (b) |- (ab.center);
\draw  (c) |- (cd.center);
\draw  (d) |- (cd.center);
\draw  (e) |- (cde.center);
\draw  (cd.center) |- (cde.center);
\draw  (ab.center) |- (all.center);
\draw  (cde.center) |- (all.center);

\draw[->,-triangle 60] (-7,0) -- node[above]{distance} (-7,6);
\end{tikzpicture}

If you use \coordinate instead of \node, you don't need the .center.

Thank you for sharing this gist. I was getting an error because of -triangle 60 in line 21, so I removed that part -

\begin{tikzpicture}[sloped]
\node (a) at (-6,0) {a};
\node (b) at (-3,0) {b};
\node (c) at (-0.5,0) {c};
\node (d) at (0.5,0) {d};
\node (e) at (2,0) {e};
\node (ab) at (-4.5,3) {};
\node (cd) at (0,1) {};
\node (cde) at (1,2) {};
\node (all) at (-1.5,5) {};

\draw  (a) |- (ab.center);
\draw  (b) |- (ab.center);
\draw  (c) |- (cd.center);
\draw  (d) |- (cd.center);
\draw  (e) |- (cde.center);
\draw  (cd.center) |- (cde.center);
\draw  (ab.center) |- (all.center);
\draw  (cde.center) |- (all.center);

\draw[->] (-7,0) -- node[above]{distance} (-7,6);
\end{tikzpicture}

And the result was (for reference) -

A little enhance version of the above script -

\begin{tikzpicture}[sloped]
    \node (a) at (-6,0) {a};
    \node (b) at (-3,0) {b};
    \node (c) at (-0.5,0) {c};
    \node (d) at (0.5,0) {d};
    \node (e) at (2,0) {e};
    \node (ab) at (-4.5,3) {};
    \node (cd) at (0,1) {};
    \node (cde) at (1,2) {};
    \node (all) at (-1.5,4.5) {};
    
    \draw  (a) |- (ab.center);
    \draw  (b) |- (ab.center);
    \draw  (c) |- (cd.center);
    \draw  (d) |- (cd.center);
    \draw  (e) |- (cde.center);
    \draw  (cd.center) |- (cde.center);
    \draw  (ab.center) |- (all.center);
    \draw  (cde.center) |- (all.center);
    
    \draw[<-] (-10,0) -- node[above]{similarity} (-10,5);    
    \draw[->] (-9,0) -- node[above]{distance} (-9,5);
    
    \draw (-7,0) -- (-7,5);
    
    \foreach \y in {0,1,2,3,4,5}                     
    \draw[shift={(0,\y)},color=black] (-7,0) -- (-7.1,0);
    
    \node[left] at (-7.1,0) {$1.0$} ;
    \node[left] at (-7.1,1) {$0.8$} ;
    \node[left] at (-7.1,2) {$0.6$} ;
    \node[left] at (-7.1,3) {$0.4$} ;
    \node[left] at (-7.1,4) {$0.2$} ;
    \node[left] at (-7.1,5) {$0.0$} ;
    
    \draw[dashed,color=gray] (-7,3.5) -- node[at end, right]{cut-off} (2.5,3.5);
    \draw[color=gray] (-7,3.5) -- (-7.1,3.5) node[left] {$0.3$} ;
\end{tikzpicture}

The result is -