dot2tex - A Graphviz to LaTeX converter

Author: Kjell Magne Fauske
Version: 2.0.3
Licence:MIT

dot2tex is a tool for converting graphs generated by Graphviz to formats suitable for use with LaTeX. Currently dot2tex can generate code for use with PSTricks and PGF/TikZ.

The purpose of dot2tex is to give graphs a more LaTeX look and feel. This is accomplished by:

Dependencies

The following software and modules are required to run dot2tex:

Users have reported problems using dot2tex with old versions of pyparsing and Graphviz.

Dot2tex was developed and tested using Python 2.4. However, dot2tex will probably run fine using Python 2.3.

Usage

Syntax:

dot2tex [options] [inputfile]

Input data is read from standard input if no input file is specified. Output is written to standard output unless a destination file is set with the -o option.

Dot2tex relies on the xdot format generated by Graphviz. Dot2tex will automatically try to convert an input file in the plain dot format to this format, but it is recommended to feed xdot data directly to dot2tex due to some limitations in the pydot module.

A few examples on how to invoke dot2tex:

Read a file from standard input and write the result to the file test.tex:

$ dot -Txdot test.dot | dot2tex > test.tex
$ neato -Txdot -Gstart=rand test.dot | dot2tex > test.tex

Load test.dot, convert it to xdot format and output the resulting graph using PGF/TikZ to testpgf.tex:

$ dot2tex -fpgf test.dot > testpgf.tex

Note

Windows users you have to type python dot2tex.py to invoke the program. If you find this annoying, try the ExeMaker tool from effbot.org.

Options

The following options are available:

-h, --help Display help message.
-f fmt, --format fmt
 

Set output format. The following values of fmt are supported:

pgf
PGF/TikZ. Default.
pstricks or pst
Use PSTricks.
tikz
TikZ format.
-t mode, --texmode mode
 

Text mode. Specify how text is converted.

verbatim
Text is displayed with all special TeX chars escaped (default).
math
Output all text in math mode $$.
raw
Output text without any processing.

Note that you can locally override the text mode by assigning a special texlbl attribute to a graph element, or by using the texmode attribute.

-s, --straightedges
 Draw edges using straight lines. Graphviz uses bezier curves to draw straight edges. Use this option to force the use of line to operations instead of curves. Does not work in duplicate mode.
-o filename, --output filename
 Write output to file.
-d, --duplicate
 Duplicate the xdot output. Uses the drawing information embedded in the xdot output to draw nodes and edges.
--template filename
 Use template from file. See the templates section for more details.
-V, --version Print version information and exit.
-w, --switchdraworder
 Switch drawing order of nodes and edges. By default edges are drawn before nodes.
-c, --crop Use preview.sty to crop the graph. Currently only implemented for the PGF/TikZ output format.
--figonly Output the graph without a document preamble. Useful if the graph is to be included in a master document.
--preproc Preprocess the graph through LaTeX using the preview package. Will generate a new dot file where the height and widths of nodes and edge labels are set based on the results from preview.
--usepdflatex Use pdflatex instead of latex for preprocessing the graph.
--nominsize Ignore minimum node sizes during preprocessing.
--valignmode mode
 

Vertical alignment of node labels, where mode can have the values:

center
Labels are placed in the middle of the node (default).
dot
Use the coordinate given by the xdot output from Graphviz.
--alignstr

Used to pass a default alignment string to the PSTricks \rput command:

\rput[alignstr] ...

Only works for the PSTricks format. PGF/TikZ users can instead pass an anchor=... style using the graphstyle option.

--debug Write detailed debug information to the file dot2tex.log in the current directory.

The following options are used by the output templates.

-e encoding, --encoding encoding
 

Set text encoding. Supported encodings are:

  • utf8
  • latin1
--docpreamble TeXcode
 Insert TeX code in the document preamble.
--figpreamble TeXcode
 Insert TeX code in the figure preamble.
--figpostamble TeXcode
 Insert TeX code in the figure postamble.
--graphstyle style
 Sets the <<graphstyle>> tag.
--margin margin
 Set margin around the graph when using preview.sty. margin must be a valid TeX unit. By default margin is set to 0pt.

Output formats

The output format is specified with the -f fmt or --format fmt command line option.

PGF and TikZ

This is the default output format. Generates code for the Portable Graphics Format (PGF) package . Mixes both PGF and TikZ commands.

PSTricks

Generates code for the PSTricks package.

TikZ

Not implemented yet. This purpose of the TikZ output format is to use TikZ' node and edge commands, instead of relying on the xdot draw commands. This will allow tighter integration with PGF/TikZ and better visual results.

Labels

The main purpose of dot2tex is to allow text and labels to be typeset by LaTeX. Labels are treated differently according to the current TeX mode:

verbatim
Text is displayed with all special TeX chars escaped (default).
math
Output all text in math mode $$.
raw
Output text without any processing.

The TeX mode can be set on the command line using the -t option. It can also be set locally in a graph by using the special texmode attribute.

You can also use the special texlbl attribute on a graph element. If a texlbl attribute is found, it will be used regardless of the current text mode.

Note

The \ character needs to be escaped with \\ if used in the label attribute.

Note that only position and alignment information is converted. Any font information is lost. This may result in some odd behavior. Some tweaking may be necessary to get it right.

Note

If you use texlbl for edges, you have to provide a dummy label attribute. Otherwise Graphviz will not generate the necessary code for placing edge labels.

Label examples

Consider the following graph:

digraph G {
    a_1-> a_2 -> a_3 -> a_1;
}

Converting the graph using:

$ dot2tex -tmath ex1.dot > ex1.tex

gives the result shown in the left hand side of the figure below. The default rendering is shown to the right. Using the raw mode will result in a compilation error because of the underscore character.

Difference between math and verbatim mode

Example of using texlbl:

digraph G {
    a_1 [texlbl="$\frac{\gamma}{x^2}$"];
    a_1-> a_2 -> a_3 -> a_1;
}
Using the special texlbl attribute

Example of using the texmode attribute:

digraph G {
    a_1 [texlbl="$\frac{\gamma}{2x^2+y^3}$"];
    a_1 -> a_2 -> a_3 -> a_1
    node [texmode="math"];
    a_1 -> b_1 -> b_2 -> a_3;
    b_1 [label="\\frac{\\gamma}{x^2}"];
    node [texmode="verbatim"]
    b_4 [label="\\beta"]
    a_3 -> b_4 -> a_1;d
}
Using the special texmode attribute

The above example shows two important things:

  • The backslash \ character needs to be written as \\ in the label attribute.
  • Using LaTeX markup in the label attribute gives oversized nodes. A workaround is to use the texlbl attribute, and manually pad the label attribute to an appropriate length. A much better solution is to use the --preproc option.

Preprocessing the above graph with:

$ dot2tex --preproc ex4.dot | dot2tex > ex4.tex

gives correctly sized nodes:

Preprocessing the graph to get correct node sizes.

Preprocessing the graph

A problem with using LaTeX for typesetting node and edge labels, is that Graphviz does not know the sizes of the resulting labels. To circumvent this problem, you can use the --preproc option. The following will then happen:

  1. Node and edge labels are extracted and the corresponding LaTeX markup is saved to a temporary file.
  2. The file is typeset with LaTeX and information about sizes is extracted using the preview package.
  3. A new dot file is created where node and edge label sizes are set using the dot language's width and height attributes.
  4. The generated graph can now be processed using Graphviz and dot2tex. Label sizes will now correspond with the output from LaTeX.

Widths and heights of nodes are handled the in same way as Graphviz does it. The width and height attributes set the minimum size of the node. If label size + margins is larger that the minimum size, the node size will grow accordingly. Default values are width=0.75in and height=0.5in.

Node margins are set using the margin attribute. This also works for edge labels. margin==value sets both the horizontal and vertical margin to value, margin=="hvalue,vvalue" sets the horizontal and vertical margins respectively.

Note that all sizes are given in inches.

If you do not want a minimum node size, you can use the '--nominsize' option. Dot2tex will then use size of label + margins as node size.

Nodes with fixedsize=True attributes are not processed.

Limitations

  • Does not work for HTML-labels
  • Does not work for record-based nodes

Examples

Consider the following graph:

digraph G {
    node [shape=circle];
    a_1 [texlbl="$x^2+\frac{\sin y}{y^2+\cos \beta}+\gamma_3$"];
    a_1 -> a_2 [label=" ", texlbl="$x_1+x_3^2+z+c+v~~$"];
    a_2 -> a_1;
}

Rendered with:

$ dot2tex -tmath example.dot > example.tex

the graph will look like this:

Graph with oversized edge and node labels

You could improve the result by adding a longer label attribute or setting a fixed width. A better solution is to preprocess the graph like this:

$ dot2tex -tmath --preproc example.dot > exampletmp.dot
$ dot2tex exampletmp.dot > example.tex

You can also chain the commands:

$ dot2tex -tmath --preproc example.dot | dot2tex > example.tex

The resulting graph now has correctly sized nodes and edge labels:

Graph with preprocessed labels

Modifying node sizes using the widht/height and margin attributes can be a bit counterintuitive. A few examples will hopefully make it clearer:

digraph G {
    node [shape=rectangle];
    a_1 [margin="0"];
    a_2 [margin="0.7,0.4"];
    a_3 [width="2",height="1"];
    a_1-> a_2 -> a_3 -> a_1;
}

Processing the graph with:

$ dot2tex -tmath --preproc example.dot | dot2tex > example.tex

gives

Graph with preprocessed labels

Setting the margin of a_1 to 0 has no effect because of the minimum node width. Processing the graph with:

$ dot2tex -tmath --preproc --nominwidth example.dot | dot2tex > example.tex

gives a different graph, where only label widths and margins affect the node sizes:

Graph with preprocessed labels

Vertical label alignment

Dot2tex relies on the xdot format for drawing nodes and placing node labels. The fonts that Graphviz and LaTeX use are different, so using the label coordinates from Graphviz does not always give good results. Dot2tex's default behavior is to place node labels in the middle of the node. However, you can change this behavior by setting the valignmode option to dot. Labels will then be placed using the coordinates supplied by Graphviz.

Here is an example graph where it is necessary to use the valignmode option:

digraph G {
    node0 [label="{left|right}", shape=record];
    node1 [shape=rectangle, label="node 1"];
    node0 -> node1;
    rankdir=LR;
}

For record nodes dot2tex has to use Graphviz coordinates. This is shown in the following figure rendered with:

$ dot2tex valign.dot
blabla

To get the same vertical alignment for both nodes, you can use:

$ dot2tex --valignmode=dot valign.dot
blabla

Now the labels are aligned, but the labels are still placed too low. The reason for this is that both PSTricks and PGF by default centers text vertically on the current coordinate. The alignment point should in this case be set to the baseline. For PGF/TikZ you can use the --graphstyle option like this:

$ dot2tex --valignmode=dot --graphstyle="anchor=base" valign.dot

PSTricks users have to use the --alingstr option:

$ dot2tex --valignmode=dot --alignstr=B valign.dot
blabla

The result is better, but to get even better alignment you have to change the node font size. Graphviz' default font size is 14pt, which is larger than the typical 10pt or 11pt used in LaTeX documents. By changing the node font size to 10pt we can trick Graphviz to give us a better alignment:

digraph G {
    node [fontsize=10];
    node0 [label="{left|right}", shape=record];
    node1 [shape=rectangle, label="node 1"];
    node0 -> node1;
    rankdir=LR;
}
blabla

Color support

All Graphviz color formats are supported, including the RGBA format. Transparency will however only work when using the PGF/TikZ output format.

Named colors are supported, but you have to ensure that the colors are defined in the resulting LaTeX file. The default PSTricks and PGF/TikZ templates load the X11names color scheme defined in the xcolor package. Note that color names in the xcolor package are case sensitive. This is not the case with Graphviz's color names. Use CamelCase names in your graphs to ensure compatibility with xcolor.

For convenience, a color definition file gcols.tex is distributed with dot2tex. You can find it in the examples directory. This file defines most of Graphviz's named colors as lower case. Include this file in the preamble if you need it.

Customizing the output

Dot2tex offers a few ways of modifying the generated output.

Using styles

The dot language defines the style attribute that can be used to modify the appearance of graphs, nodes, and edges. The style attribute is passed to the rendering backend, and is a powerful and flexible way of customizing the look and feel of your graphs. Using styles requires detailed knowledge of the output format.

The following example shows how interesting visual results can be achieved with the PGF/TikZ output format. The styles are PGF/TikZ specific. See the user guide for details:

graph G {
    node [shape=circle, fixedsize=True, width="0.2",
          style="ball color =green", label=""];
    edge [style="snake=zigzag, green"];
    a_1 -- c -- a_2;
    c [style="ball color=black"];
    edge [style="snake=snake, blue"];
    node [style="ball color = red", label=""];
    a_3 -- c -- a_4 --a_3;
}

The snake styles only work on straight lines. We therefore have to use the -s option. fdp is used to lay out the graph:

$ fdp -TXdot ball.dot | dot2tex -fpgf -s > balls.tex

The resulting graph is shown below.

Using styles to style the PGF/TikZ output.

Note

Use the straight edge option -s to force the use of straight lines. Otherwise curves will be used to draw even straight lines.

Changing arrow types

The style attribute can be used to change arrow types. A PGF/TikZ example:

digraph G {
    graph [mindist=0.5];
    node [fixedsize=true, shape=circle, width=0.4, style="fill=green!20"];
    c -> n_1 [style="-stealth"];
    c -> n_2 [style="-to"];
    c -> n_3 [style="-latex"];
    c -> n_4 [style="-diamond"];
    c -> n_5 [style="-o"];
    c -> n_6 [style="{-]}"];
    c -> n_7 [style="-triangle 90"];
    c -> n_8 [style="-hooks"];
    c -> n_9 [style="->>"];
    c [style="fill=red!80"];
}

Rendered with:

$ circo -Txdot pgfarrows.dot | dot2tex -fpgf > pgfarrows.tex
PGF/TikZ style arrows.

You can also set the default arrow style by using the --graphstyle option or d2tgraphstyle attribute:

$ dot2tex -tmath --graphstyle=">=diamond" ex1.dot > ex1gstyle.tex
Setting default PGF/TikZ arrows.

A PSTricks example:

digraph G {
    d2tdocpreamble="\usepackage{pstricks-add}";
    graph [mindist=0.5];
    node [texmode="math", fixedsize=true, shape=circle, width=0.4];
    c -> n_1 [style="arrows=->"];
    c -> n_2 [style="arrows=->>"];
    c -> n_3 [style="arrows=-<"];
    c -> n_4 [style="arrows=-*"];
    c -> n_5 [style="arrows=-{]}"];
    c -> n_6 [style="arrows=-o"];
    c -> n_7 [style="arrows=-H"];
    c -> n_8 [style="arrows=->];
}

Rendered with:

$ circo -Txdot pstarrows.dot | dot2tex -fpst > pstarrows.tex
PSTricks style arrows

The above example shows how the d2tdocpreamble attribute can be used to load additional LaTeX packages. You could also use the `--docpreamble option:

$ ... | dot2tex -fpst --docpreamble="\usepackage{pstricks-add}" ...

Templates

The output from dot2tex is a list of drawing commands. To render the graphics with LaTeX there's a need for some boiling plate code. This code can be customized using simple templates. If no template is specified with the -t option, a default template will be used.

The following template tags are available:

<<drawcommands>>
The actual list of drawing commands.
<<figcode>>
Drawing commands wrapped in a figure environment. Note that several important style options are set in the figure environment.
<<bbox>>

Bounding box. Example: (0bp,0bp)(100bp,100bp) The individual parts of the bounding box are available with the tags:

  • <<bbox.x0>>
  • <<bbox.y0>>
  • <<bbox.x1>>
  • <<bbox.y1>>

Note that the bounding box parts are given without any units.

<<textencoding>>
The text encoding used for the output file. Current values are: - utf8 - latin1
<<docpreamble>>
Document preamble. The content of this tag is set by the --docpreamble option or d2tdocpreamble graph attribute. Useful for including packages and such.
<<figpreamble>>
Figure preamble. The content of this tag is set by the --figpreamble option or d2tfigpreamble graph attribute. Useful for setting font sizes and such.
<<preproccode>>
Code generated for preprocessing labels.

Three different templates are used by dot2tex for the preprocessing mode, output mode and figure only mode respectively. The following template tags make it possible to use the same template file for all modes.

<<startoutputsection>> and <<endoutputsection>>
Code between these tags is ignored in preprocessing mode.
<<startpreprocsection>> and <<endpreprocsection>>
Code between these tags is ignored in output mode.
<<startfigonlysection>> and <<endfigonlysection>>
Code between these tags is used as a template when using the --figonly option. Ignored in preprocessing and output mode.

Note

Tags that have no value are replaced with an empty string. Insert a % character after a template tag to avoid unwanted line breaks.

Default PGF/TikZ template

\documentclass{article}
\usepackage[x11names, rgb]{xcolor}
\usepackage[<<textencoding>>]{inputenc}
\usepackage{tikz}
\usetikzlibrary{snakes,arrows,shapes}
\usepackage{amsmath}
<<startpreprocsection>>%
\usepackage[active,auctex]{preview}
<<endpreprocsection>>%
<<gvcols>>%
<<cropcode>>%
<<docpreamble>>%

\begin{document}
\pagestyle{empty}
%
<<startpreprocsection>>%
<<preproccode>>
<<endpreprocsection>>%
%
<<startoutputsection>>
\enlargethispage{100cm}
% Start of code
% \begin{tikzpicture}[anchor=mid,>=latex',join=bevel,<<graphstyle>>]
\begin{tikzpicture}[>=latex',join=bevel,<<graphstyle>>]
\pgfsetlinewidth{1bp}
<<figpreamble>>%
<<drawcommands>>
<<figpostamble>>%
\end{tikzpicture}
% End of code
<<endoutputsection>>
%
\end{document}
%
<<startfigonlysection>>
\begin{tikzpicture}[>=latex,join=bevel,<<graphstyle>>]
\pgfsetlinewidth{1bp}
<<figpreamble>>%
<<drawcommands>>
<<figpostamble>>%
\end{tikzpicture}
<<endfigonlysection>>

The <<cropcode>> template tag is available when the --preview option is used. The contents will then be:

\usepackage[active,tightpage]{preview}
\PreviewEnvironment{tikzpicture}
\setlength\PreviewBorder{<<margin>>}

Default pstricks template

\documentclass{article}
% <<bbox>>
\usepackage[x11names]{xcolor}
\usepackage[<<textencoding>>]{inputenc}
\usepackage{graphicx}
\usepackage{pstricks}
\usepackage{amsmath}
<<startpreprocsection>>%
\usepackage[active,auctex]{preview}
<<endpreprocsection>>%
<<gvcols>>%
<<docpreamble>>%


\begin{document}
\pagestyle{empty}
<<startpreprocsection>>%
<<preproccode>>%
<<endpreprocsection>>%
<<startoutputsection>>%
\enlargethispage{100cm}

% Start of code
\begin{pspicture}[linewidth=1bp<<graphstyle>>]<<bbox>>
\pstVerb{2 setlinejoin} % set line join style to 'mitre'
<<figpreamble>>%
<<drawcommands>>
<<figpostamble>>%
\end{pspicture}
% End of code
<<endoutputsection>>%
\end{document}
%
<<startfigonlysection>>
\begin{pspicture}[linewidth=1bp<<graphstyle>>]<<bbox>>
\pstVerb{2 setlinejoin} % set line join style to 'mitre'
<<figpreamble>>%
<<drawcommands>>
<<figpostamble>>%
\end{pspicture}
<<endfigonlysection>>

Special attributes

Dot2tex defines several special graph, node and edge attributes. Most of them are not part of the DOT language.

texmode
Changes locally how labels are interpreted.
texlbl
Overrides the current node or edge label.
d2tdocpreamble
Sets the <<docpreamble>> tag.
d2tfigpreamble
Sets the <<figpreamble>> tag.
d2tfigpostamble
Sets the <<figpostable>> tag.
d2tgraphstyle
Sets the <<graphstyle>> tag.
style
Used to pass styles to the backend. Styles are output format specific, with the exception of the styles defined by the DOT language.
d2talignstr

Used to pass a default alignment string to the PSTricks \rput command:

\rput[d2talignstr] ...

Issues and limitations

The purpose of dot2tex is to give graphs a more LaTeX friendly look, not to create exact duplicates. However, the program does a descent duplication job when it comes to drawing nodes and edges, but it does not try to duplicate label and annotation formatting.

A list of known limitations:

Text encoding

Graphviz's default text encoding is utf8. The latin1 encoding can also be used. Utf8 is an unicode encoding and can in theory handle any international characters. However, LaTeX's unicode support is somewhat limited.

Tips and tricks

Fonts

No font information in the DOT file is preserved by dot2tex. However, there are several ways of modifying the generated LaTeX code to achieve some control of fonts and font sizes.

  • Modifying the templates.
  • Using the d2tdocpreamble and d2tfigpreamble attributes or command line options.

To increase the font size you can for instance insert a \Huge command in the figure preamble:

$ dot2tex -tmath --figpreamble="\Huge" ex1.dot > ex1huge.tex
Setting label font size to \Huge

Debugging

When making your own templates it is easy to make mistakes, and LaTeX markup in graphs may fail to compile. To make it easier to find errors, invoke dot2tex with the --debug option:

$ dot2tex --preproc --debug test.dot

A dot2tex.log file will then be generated with detailed information. In the log file you will find the generated LaTeX code, as well as well as the compilation log.

Be consistent

Be aware of differences between the template you use for preprocessing and code used to generate final output. This is especially important if you use the --figonly option and include the code in a master document. If a 10pt font is used during preprocessing, the result may not be optimal if a 12pt font is used in the final output.

Example. A graph is generated with:

$ dot2tex --preproc -tmath --nominsize ex1.dot > ex1tmp.dot

Running through dot2tex again with:

$ dot2tex figpreamble="\Huge" ex1tmp.dot > ex1huge.tex

gives labels that do not fit inside the nodes.

Inconsistence between preproc mode and output mode.