[comp.text.tex] Drawing trees in LaTeX

peter@dit.lth.se (Peter Vanroose) (07/12/90)

In article <50460@iuvax.cs.indiana.edu>, Raja Sooriamurthi writes:
> Have you included circuits with LaTeX text before and if so what did you use.
> Information on other packages/macros is welcome.

The following macros let you draw a (binary or ternary) tree of any size. 
For each "internal node", you only have to specify which are the descending
nodes, with a \branch command. (\tbranch for ternary node.)
To this end, nodes are given a label (only used internally!)

These macros will give you some ideas on designing similar things for, e.g., 
digital circuits. 

Trees are constructed with labels on the branches (default 0 and 1), and 
with text (e.g., its name or value) on the nodes.  The first parameter to
\branch (0, 1, 2 or 3) determines the steepness of the branches.

Example:

\begin{picture}(16,12)
\setlength\unitlength{2mm}
\branchlabels ABC           % 012 is the default
\root(2,10)          0.     % root at absolute coordinate (2,10) 
                            % its (internally used) label is 0
                            % the space before the 0 is obligatory
\branch2{16}         0:1,2. % node 0 (i.e., the root) has children 1 and 2
                            % the text "1.00" is written above it
                            % space is optional, :,. are obligatory 
  \leaf{4}{$u_1$}    1.     % node 1 is a leaf
                            % "0.45" written above, "$u_1$" to the right
  \branch2{12}       2:3,7. % branch to node 3 goes up, and has label A
    \tbranch2{9}     3:4,5,6.
      \leaf{4}{$u_3$}4.     % the symbols 0--7 can be replaced by anything
      \leaf{3}{$u_4$}5.
      \leaf{2}{$u_5$}6.
    \leaf{3}{$u_2$}  7.
\end{picture}

will typeset something like 

           4         4
           . u       . u
          /   1    A/   3
        A/         /
      16/       9 /  3
   +--./        ./_B_. u
  -+-  \       / \C     4
        \B   A/   \
         \ 12/     \ 2
          \./       \. u
            \B          5
             \
              \ 3
               \. u
                   2

    Peter Vanroose
    peter@dit.lth.se

%---------- trees.sty --------------------
% Peter Vanroose, 18 april 1990.
\newcount\branchwidth\newcount\xcoord\newcount\ycoord\newcount\coordstep
\def\branchlabels#1#2#3{\edef\labela{#1}\edef\labelb{#2}\edef\labelc{#3}}
\branchlabels012
%
\def\root(#1,#2) #3.{\catcode32=9       % ignore spaces
              %  #3 is the node label of the root
 \expandafter\xdef\csname nodex#3\endcsname{#1}
 \expandafter\xdef\csname nodey#3\endcsname{#2}
 \put(#1,#2){
  \put(0,0){\line(-1,0)6}\put(-6,0){\line(0,-1)3}\put(-9,-3){\line(1,0)6}}}
%
\def\branch#1#2#3:#4,#5.{ \branchwidth=#1
 \xcoord=\expandafter\number\csname nodex#3\endcsname
 \ycoord=\expandafter\number\csname nodey#3\endcsname
 \edef\coord{(\number\xcoord,\number\ycoord)}
 \advance\xcoord by 12      %  #4,#5 are the labels of the childs
 \expandafter\xdef\csname nodex#4\endcsname{\number\xcoord}
 \expandafter\xdef\csname nodex#5\endcsname{\number\xcoord}
 \ifcase\branchwidth
  \advance\ycoord by 24\coordstep=-48 \or % case 0
  \advance\ycoord by 12\coordstep=-24 \or % case 1
  \advance\ycoord by  6\coordstep=-12 \or % case 2
  \advance\ycoord by  3\coordstep=- 6 \fi % case 3
 \expandafter\xdef\csname nodey#4\endcsname{\number\ycoord}
 \advance\ycoord by \coordstep
 \expandafter\xdef\csname nodey#5\endcsname{\number\ycoord}
 \expandafter\put\coord{
  \put(0,0){\circle*1}\put(0,1.5){\makebox(0,0){\scriptsize #2}}
  \ifcase\branchwidth
   \put(0,0){\line(1,2){12}}\put(0,0){\line(1,-2){12}}
   \put(5,12){\tiny$\labela$}\put(5,-12){\tiny$\labelb$} \or % case 0
   \put(0,0){\line(1,1){12}}\put(0,0){\line(1,-1){12}}
   \put(6,7){\tiny$\labela$}\put(6,-8){\tiny$\labelb$}   \or % case 1
   \put(0,0){\line(2,1){12}}\put(0,0){\line(2,-1){12}}
   \put(6,3.6){\tiny$\labela$}\put(6,-5){\tiny$\labelb$} \or % case 2
   \put(0,0){\line(4,1){12}}\put(0,0){\line(4,-1){12}}
   \put(6,2){\tiny$\labela$}\put(6,-3){\tiny$\labelb$}   \fi % case 3
}}
%
\def\tbranch#1#2#3:#4,#5,#6.{
 \branchwidth=#1
 \xcoord=\expandafter\number\csname nodex#3\endcsname
 \ycoord=\expandafter\number\csname nodey#3\endcsname
 \edef\coord{(\number\xcoord,\number\ycoord)}
 \advance\xcoord by 12
 \expandafter\xdef\csname nodex#4\endcsname{\number\xcoord}
 \expandafter\xdef\csname nodex#5\endcsname{\number\xcoord}
 \expandafter\xdef\csname nodex#6\endcsname{\number\xcoord}
 \ifcase\branchwidth
  \advance\ycoord by 24\coordstep=-24 \or % case 0
  \advance\ycoord by 12\coordstep=-12 \or % case 1
  \advance\ycoord by  6\coordstep= -6 \or % case 2
  \advance\ycoord by  3\coordstep= -3 \fi % case 3
 \expandafter\xdef\csname nodey#4\endcsname{\number\ycoord}
 \advance\ycoord by \coordstep
 \expandafter\xdef\csname nodey#5\endcsname{\number\ycoord}
 \advance\ycoord by \coordstep
 \expandafter\xdef\csname nodey#6\endcsname{\number\ycoord}
 \expandafter\put\coord{
  \put(0,0){\circle*1}\put(0,1.5){\makebox(0,0){\scriptsize #2}}
  \ifcase\branchwidth
   \put(0,0){\line(1,2){12}}\put(0,0){\line(1,0){12}}\put(0,0){\line(1,-2){12}}
   \put(5,12){\tiny$\labela$}\put(5,0.6){\tiny$\labelb$}\put
     (5,-12){\tiny$\labelc$} \or % case 0
   \put(0,0){\line(1,1){12}}\put(0,0){\line(1,0){12}}\put(0,0){\line(1,-1){12}}
   \put(6,7){\tiny$\labela$}\put(6,0.5){\tiny$\labelb$}\put
     (6,-8){\tiny$\labelc$}  \or % case 1
   \put(0,0){\line(2,1){12}}\put(0,0){\line(1,0){12}}\put(0,0){\line(2,-1){12}}
   \put(6,3.6){\tiny$\labela$}\put(6,0.5){\tiny$\labelb$}\put
     (6,-5){\tiny$\labelc$}  \or % case 2
   \put(0,0){\line(4,1){12}}\put(0,0){\line(1,0){12}}\put(0,0){\line(4,-1){12}}
   \put(6,2){\tiny$\labela$}\put(6,0.25){\tiny$\labelb$}\put
     (6,-3){\tiny$\labelc$}    \fi % case 3
}}
%
\def\leaf#1#2#3.{
 \xcoord=\expandafter\number\csname nodex#3\endcsname
 \ycoord=\expandafter\number\csname nodey#3\endcsname
 \edef\coord{(\number\xcoord,\number\ycoord)}
 \expandafter\put\coord{
  \put(0,0){\circle*1}\put(0,1.5){\makebox(0,0){\scriptsize #1}}
  \put(2,-0.6){\makebox(0,0)[l]{#2}}}}
%
%-------- end of trees.sty -------------