Text wrapping with dot (graphviz) - graphviz

Question

I used the code below to create a graphic using dot (graphviz).
digraph
{
node [color=Blue,shape=box]
1.1 [label="Frequency of t exceeds upper threshold"]
2.1 [label="t has d-mutant tiles"]
2.2 [label="Valid"]
3.1 [label="Frequency of t exceeds lower threshold"]
3.2 [label="Frequency of t exceeds lower threshold"]
4.1 [label="Insufficient evidence"]
4.2 [label="Valid"]
4.3 [label="t has only one d-mutant that exceeds lower threshold"]
4.4 [label="Are there any d-mutant tiles with significantly higher frequencies?"]
5.1 [label="Insufficient evidence"]
node [color=Green] 5.2 [label="Correct t to t'"] node [color=Blue]
5.3 [label="t has a d-mutant tile t' that is closer than all other d-mutant tiles and for which a corrected base has a higher quality score"]
5.4 [label="Valid"]
6.1 [label="Insufficient evidence"]
6.2 [label="t' is unique"]
7.1 [label="Insufficient evidence"]
node [color=Green] 7.2 [label="Correct t to t'"] node [color=Blue]
1.1 -> 2.1 [label="no"]
1.1 -> 2.2 [label="yes"]
2.1 -> 3.1 [label="no"]
2.1 -> 3.2 [label="yes"]
3.1 -> 4.1 [label="no"]
3.1 -> 4.2 [label="yes"]
3.2 -> 4.3 [label="no"]
3.2 -> 4.4 [label="yes"]
4.3 -> 5.1 [label="no"]
4.3 -> 5.2 [label="yes"]
4.4 -> 5.3 [label="no"]
4.4 -> 5.4 [label="yes"]
5.3 -> 6.1 [label="no"]
5.3 -> 6.2 [label="yes"]
6.2 -> 7.1 [label="no"]
6.2 -> 7.2 [label="yes"]
}
As you can see, some of the boxes in the graphic have a lot of text in the label. I can insert \n characters to make sure the boxes aren't too wide, but I'm wondering if there is a way I can set the width of the boxes and then have the box labels do a hard wrap. Is this possible?

Answer 1

graphviz doesn't support automatic line breaks. You have to put the \n in manually.
you can set a width and a height to a node and define it as fixedsized - this will
limit the size of the node and draw only as much text as fits into the node

Answer 2

Although graphviz does not support text wrapping by itself,
dot2tex (latex+graphviz) does.
The dot2texi latex package gives an all-in-one solution,
with (from the users point of view) a single call to a single tool to build the graph.
A short example:
\documentclass{standalone}
\usepackage{dot2texi}
\usepackage{tikz}
\usetikzlibrary{shapes,arrows}
\begin{document}
\begin{dot2tex}[dot]
digraph G {
d2toptions ="--autosize"
node [lblstyle="text width=10em,align=center"]
a [texlbl="This text will be automatically wrapped, for example at a fixed width."]
b [texlbl="Manual linebreaks from past century can be avoided!"]
a -> b
}
\end{dot2tex}
\end{document}
This can be compiled invoking for example: pdflatex --shell-escape myFile.tex, the text will be automatically wrapped at the prescribed fixed width.
As a side note, this tool seems a handy workaround for graphviz' limited typesetting control of the nodes contents.

Answer 3

The OP wrote a whole Perl script to achieve this. I found it in his blog: Text wrapping with dot (graphviz).
⚠ Note
This only works if the labels are in the format node [ label=”node label” ]. If the nodes are declared directly (e.g. ”node label”) then it doesn’t work
Perl script:
#!/usr/bin/perl
use strict;
my $usage = "setdotlabelwidth [char-width] < [dotfile]";
my $width = shift() or die("Usage: $usage $!");
while(<STDIN>)
{
if(m/label="(.*?)"/)
{
my $labeltext = $1;
my #words = split(/ /, $labeltext);
my #newtext = ();
my $newline = "";
foreach my $word(#words)
{
if( length($newline) > 0 and
length($newline) + length($word) > $width )
{
push(#newtext, $newline);
$newline = "";
}
$newline .= " " if( length($newline) > 0 );
$newline .= $word;
}
push(#newtext, $newline) if( length($newline) > 0 );
my $newlabel = join("\\n", #newtext);
s/label=".*?"/label="$newlabel"/;
}
print;
}
Save this program as setdotlabelwidth, then simply pipe the output into GraphViz. If for example you want to set the width to 35 characters, then the command is:
./setdotlabelwidth 35 < tile-error-correction.dot | dot -Tpng -o tile-error-correction.png
Before:
After: