Tribblix: manual page: dot.1

DOT(1) User Commands DOT(1)

NAME

dot - filter for drawing directed graphs
neato - filter for drawing undirected graphs
twopi - filter for radial layouts of graphs
circo - filter for circular layout of graphs
fdp - filter for drawing undirected graphs
sfdp - filter for drawing large undirected graphs
patchwork - filter for squarified tree maps
osage - filter for array-based layouts

SYNOPSIS

dot [options] [files]
neato [options] [files]
twopi [options] [files]
circo [options] [files]
fdp [options] [files]
sfdp [options] [files]
patchwork [options] [files]
osage [options] [files]

DESCRIPTION

These are a collection of programs for drawing graphs. There is
actually only one main program; the specific layout algorithms are
implemented as plugins. Thus, they largely share all of the same
command-line options.

dot draws directed graphs. It works well on directed acyclic graphs
and other graphs that can be drawn as hierarchies or have a natural
``flow.''

neato draws undirected graphs using a ``spring'' model and reducing
the related energy (see Kamada and Kawai, Information Processing
Letters 31:1, April 1989).

twopi draws graphs using a radial layout (see G. Wills, Symposium on
Graph Drawing GD'97, September, 1997). Basically, one node is chosen
as the center and put at the origin. The remaining nodes are placed
on a sequence of concentric circles centered about the origin, each a
fixed radial distance from the previous circle. All nodes distance 1
from the center are placed on the first circle; all nodes distance 1
from a node on the first circle are placed on the second circle; and
so forth.

circo draws graphs using a circular layout (see Six and Tollis, GD
'99 and ALENEX '99, and Kaufmann and Wiese, GD '02.) The tool
identifies biconnected components and draws the nodes of the
component on a circle. The block-cutpoint tree is then laid out using
a recursive radial algorithm. Edge crossings within a circle are
minimized by placing as many edges on the circle's perimeter as
possible. In particular, if the component is outerplanar, the
component will have a planar layout. If a node belongs to multiple
non-trivial biconnected components, the layout puts the node in one
of them. By default, this is the first non-trivial component found in
the search from the root component.

fdp draws undirected graphs using a ``spring'' model. It relies on a
force-directed approach in the spirit of Fruchterman and Reingold
(cf. Software-Practice & Experience 21(11), 1991, pp. 1129-1164).

sfdp also draws undirected graphs using the ``spring'' model
described above, but it uses a multi-scale approach to produce
layouts of large graphs in a reasonably short time.

patchwork draws the graph as a squarified treemap (see M. Bruls et
al., ``Squarified treemaps'', Proc. Joint Eurographics and IEEE TCVG
Symp. on Visualization, 2000, pp. 33-42). The clusters of the graph
are used to specify the tree.

osage draws the graph using its cluster structure. For a given
cluster, each of its subclusters is laid out internally. Then the
subclusters, plus any remaining nodes, are repositioned based on the
cluster's pack and packmode attributes.

OUTPUT FORMATS

Graphviz uses an extensible plugin mechanism for its output
renderers, so to see what output formats your installation of dot
supports you can use ``dot -T:'' and check the warning message.
Also, The plugin mechanism supports multiple implementations of the
output formats, allowing variations in the renderers and formatters.
To see what variants are available for a particular output format,
use, for example: ``dot -Tpng:'' and to force a particular variant,
use, for example: ``dot -Tpng:gd''

Traditionally, Graphviz supports the following:
-Tdot (Dot format containing layout information),
-Txdot (Dot format containing complete layout information),
-Tps (PostScript),
-Tpdf (PDF),
-Tsvg -Tsvgz (Structured Vector Graphics),
-Tfig (XFIG graphics),
-Tpng (png bitmap graphics),
-Tgif (gif bitmap graphics),
-Tjpg -Tjpeg (jpeg bitmap graphics),
-Tjson (xdot information encoded in JSON),
-Timap (imagemap files for httpd servers for each node or edge that
has a non-null href attribute.),
-Tcmapx (client-side imagemap for use in html and xhtml).
Additional less common or more special-purpose output formats can be
found at https://www.graphviz.org/doc/info/output.html.

Alternative plugins providing support for a given output format can
be found from the error message resulting from appending a ':' to the
format. e.g. -Tpng: The first plugin listed is always the default.

The -P switch can be used to produce a graph of all output variants
supported by plugins in the local installation of graphviz.

GRAPH FILE LANGUAGE

Here is a synopsis of the graph file language, normally using the
extension .gv, for graphs:

[strict] (graph|digraph) name { statement-list }
is the top-level graph. If the graph is strict, then multiple edges
are not allowed between the same pairs of nodes. If it is a directed
graph, indicated by digraph, then the edgeop must be "->". If it is
an undirected graph then the edgeop must be "--".

Statements may be:

name=val;
node [name=val];
edge [name=val];
Set default graph, node, or edge attribute name to val. Any
subgraph, node, or edge appearing after this inherits the new default
attributes.

n0 [name0=val0,name1=val1,...];
Creates node n0 (if it does not already exist) and sets its
attributes according to the optional list.

n0 edgeop n1 edgeop ... edgeop nn [name0=val0,name1=val1,...];
Creates edges between nodes n0, n1, ..., nn and sets their attributes
according to the optional list. Creates nodes as necessary.

[subgraph name] { statement-list }
Creates a subgraph. Subgraphs may be used in place of n0, ..., nn in
the above statements to create edges. [subgraph name] is optional;
if missing, the subgraph is assigned an internal name.

The language accepts both C-style comments /*C...*/ or //...

Attribute names and values are ordinary (C-style) strings. The
following sections describe attributes that control graph layout.

A more complete description of the language can be found at
https://www.graphviz.org/doc/info/lang.html.

GRAPH, NODE AND EDGE ATTRIBUTES
Graphviz uses the name=value attributes, attached to graphs,
subgraphs, nodes and edges, to tailor the layout and rendering. We
list the more prominent attributes below. The complete list is
available at https://www.graphviz.org/doc/info/attrs.html.

Attributes Common to Nodes, Edges, Clusters and Graphs
href=url the default url for image map files; in PostScript files,
the base URL for all relative URLs, as recognized by Acrobat
Distiller 3.0 and up.

URL=url (``URL'' is a synonym for ``href.'')

fontcolor=colorvalue sets the label text color.

A colorvalue may be "h,s,v" (hue, saturation, brightness) floating
point numbers between 0 and 1, or an X11 color name such as white,
black, red, green, blue, yellow, magenta, or cyan, or a "#rrggbb"
(red, green, blue, 2 hex characters each) value. See
https://www.graphviz.org/doc/info/attrs.html#k:color and
https://www.graphviz.org/doc/info/colors.html for further details.

fontsize=n sets the label type size to n points.

fontname=name sets the label font family name.

label=text where text may include escaped newlines \n, \l, or \r for
center, left, and right justified lines. The string '\G' value will
be replaced by the graph name. For node labels, the string '\N'
value will be replaced by the node name. For edges, if the substring
'\T' is found in a label, it will be replaced by the name of the tail
node; if the substring '\H' is found in a label, it will be replaced
by the name of the head node; if the substring '\E' value is found in
a label it will be replaced by: tail_node_name->head_node_name or by:
tail_node_name--head_node_name for undirected graphs.

Graphviz also supports special HTML-like labels for constructing
complex node content. A full-description of these is given at
https://www.graphviz.org/doc/info/shapes.html#html.

If a node has shape=record, the label may contain recursive box lists
delimited by { | }. Port identifiers in labels are set off by angle
brackets < >.

Graph Attributes
size="x,y" specifies the maximum bounding box of drawing in inches.

ratio=f sets the aspect ratio to f which may be a floating point
number, or one of the keywords fill, compress, or auto.

layout=engine indicates the preferred layout engine (dot, neato, fdp,
etc.) overriding the default from the basename of the command or the
-K commandline option.

margin=f sets the page margin (included in the page size).

ordering=out constrains order of out-edges in a subgraph according to
their file sequence.

rotate=90 sets landscape mode. (orientation=land is backward
compatible but obsolete.)

center=n a non-zero value centers the drawing on the page.

color=colorvalue sets foreground color (bgcolor for background).

overlap=mode. This specifies what algorithm should do if any nodes
overlap. If mode is false, the program uses the Prism algorithm to
adjust the nodes to eliminate overlaps. If mode is scale, the layout
is uniformly scaled up, preserving node sizes, until nodes no longer
overlap. The latter technique removes overlaps while preserving
symmetry and structure, while the former removes overlaps more
compactly but destroys symmetries. If mode is true (the default), no
repositioning is done. Since the dot algorithm always produces a
layout with no node overlaps, this attribute is only useful with
other layouts.

stylesheet="file.css" includes a reference to a stylesheet in -Tsvg
and -Tsvgz outputs. Ignored by other formats.

splines If set to true, edges are drawn as splines. If set to
polyline, edges are drawn as polylines. If set to ortho, edges are
drawn as orthogonal polylines. In all of these cases, the nodes must
not overlap. If splines=false or splines=line, edges are drawn as
line segments. The default is true for dot, and false for all other
layouts.

(dot-specific attributes)

nodesep=f sets the minimum separation between nodes.

ranksep=f sets the minimum separation between ranks.

rankdir=LR|RL|BT requests a left-to-right, right-to-left, or
bottom-to-top, drawing.

rank=same (or min or max) in a subgraph constrains the rank
assignment of its nodes. If a subgraph's name has the prefix
cluster, its nodes are drawn in a distinct rectangle of the layout.
Clusters may be nested.

(neato-specific attributes)
mode=val. Algorithm for minimizing energy in the layout. By default,
neato uses stress majorization. If mode=KK, it uses a version of
gradient descent.

model=val. The neato model computes the desired distances between
all pairs of vertices. By default, it uses the length of the shortest
path. If model is set to circuit, a circuit-resistance model is used.
If model is set to subset, it uses a model whereby the edge length is
the number of nodes that are neighbors of exactly one of the edge's
vertices.

start=val. Requests random initial placement and seeds the random
number generator. If val is not an integer, the process ID or
current time is used as the seed.

epsilon=n. Sets the cutoff for the solver. The default is 0.1.

(twopi-specific attributes)
root=ctr. This specifies the node to be used as the center of the
layout. If not specified, twopi will randomly pick one of the nodes
that are furthest from a leaf node, where a leaf node is a node of
degree 1. If no leaf nodes exists, an arbitrary node is picked as
center.

ranksep=val. Specifies the radial distance in inches between the
sequence of rings. The default is 0.75.

(circo-specific attributes)
root=nodename. Specifies the name of a node occurring in the root
block. If the graph is disconnected, the root node attribute can be
used to specify additional root blocks.

mindist=value. Sets the minimum separation between all nodes. If not
specified then circo uses a default value of 1.0.

(fdp-specific attributes)
K=val. Sets the default ideal node separation in the layout.

maxiter=val. Sets the maximum number of iterations used to layout the
graph.

start=val. Adjusts the random initial placement of nodes with no
specified position. If val is an integer, it is used as the seed for
the random number generator. If val is not an integer, a random
system-generated integer, such as the process ID or current time, is
used as the seed.

Node Attributes
height=d or width=d sets minimum height or width. Adding
fixedsize=true forces these to be the actual size (text labels are
ignored).

shape=builtin_polygon record epsf
builtin_polygon can be such values as plaintext, ellipse, oval,
circle, egg, triangle, box, diamond, trapezium, parallelogram, house,
hexagon, octagon, note, tab, box3d, or component,, among others.
(Polygons are defined or modified by the following node attributes:
regular, peripheries, sides, orientation, distortion and skew.) epsf
uses the node's shapefile attribute as the path name of an external
EPSF file to be automatically loaded for the node shape.

See https://www.graphviz.org/doc/info/shapes.html for a complete
description of node shapes.

color=colorvalue sets the outline color, and the default fill color
if style=filled and fillcolor is not specified.

fillcolor=colorvalue sets the fill color when style=filled. If not
specified, the fillcolor when style=filled defaults to be the same as
the outline color.

style=filled solid dashed dotted bold invis

xlabel="text" specifies a label that will be place near, but outside,
of a node. The normal label string is placed within the node shape.

target="target" is a target string for client-side imagemaps and SVG,
effective when nodes have a URL. The target string is used to
determine which window of the browser is used for the URL. Setting
it to "_graphviz" will open a new window if it doesn't already exist,
or reuse it if it does. If the target string is empty, the default,
then no target attribute is included in the output. The substrings
'\N' and '\G' are substituted in the same manner as for the node
label attribute. Additionally the substring '\L' is substituted with
the node label string.

tooltip="text" is a tooltip string for client-side imagemaps and SVG,
effective when nodes have a URL. The tooltip string defaults to be
the same as the label string, but this attribute permits nodes
without labels to still have tooltips thus permitting denser graphs.
The substrings '\N' and '\G' are substituted in the same manner as
for the node label attribute. Additionally the substring '\L' is
substituted with the node label string.

The following attributes apply only to polygon shape nodes:

regular=n if n is non-zero then the polygon is made regular, i.e.
symmetric about the x and y axis, otherwise the polygon takes on the
aspect ratio of the label. builtin_polygons that are not already
regular are made regular by this attribute. builtin_polygons that
are already regular are not affected (i.e. they cannot be made
asymmetric).

peripheries=n sets the number of periphery lines drawn around the
polygon. This value supersedes the number of periphery lines of
builtin_polygons.

sides=n sets the number of sides to the polygon. n<3 results in an
ellipse. This attribute is ignored by builtin_polygons.

orientation=f sets the orientation of the first apex of the polygon
counterclockwise from the vertical, in degrees. f may be a floating
point number. The orientation of labels is not affected by this
attribute. This attribute is added to the initial orientation of
builtin_polygons.

distortion=f sets the amount of broadening of the top and narrowing
of the bottom of the polygon (relative to its orientation). Floating
point values between -1 and +1 are suggested. This attribute is
ignored by builtin_polygons.

skew=f sets the amount of right-displacement of the top and
left-displacement of the bottom of the polygon (relative to its
orientation). Floating point values between -1 and +1 are suggested.
This attribute is ignored by builtin_polygons.

(circo-specific attributes)
root=true/false. This specifies that the block containing the given
node be treated as the root of the spanning tree in the layout.

(neato- and fdp-specific attributes)
pin=val. If val is true, the node will remain at its initial
position.

Edge Attributes
weight=val where val is the cost of the edge. For dot, weights must
be non-negative integers. Values greater than 1 tend to shorten the
edge; weight 0 flat edges are ignored for ordering nodes. In twopi,
a weight of 0 will cause the edge to be ignored in constructing the
underlying spanning tree. For neato and fdp, a heavier weight will
put more emphasis on the algorithm achieving an edge length closer to
that specified by the edge's len attribute.

style=solid dashed dotted bold invis

color=colorvalue sets the line color for edges.

color=colorvaluelist a ':' separated list of colorvalue creates
parallel edges, one edge for each color.

dir=forward back both none controls arrow direction.

tailclip,headclip=false disables endpoint shape clipping.

target="text" is a target string for client-side imagemaps and SVG,
effective when edges have a URL. If the target string is empty, the
default, then no target attribute is included in the output. The
substrings '\T', '\H', '\E' and '\G' are substituted in the same
manner as for the edge label attribute. Additionally the substring
'\L' is substituted with the edge label string.

tooltip="text" is a tooltip string for client-side imagemaps
effective when edges have a URL. The tooltip string defaults to be
the same as the edge label string. The substrings '\T', '\H', '\E'
and '\G' are substituted in the same manner as for the edge label
attribute. Additionally the substring '\L' is substituted with the
edge label string.

arrowhead,arrowtail=none, normal, inv, dot, odot, invdot, invodot,
tee, empty, invempty, open, halfopen, diamond, odiamond, box, obox,
crow. Specifies the shape of the glyph occurring where the edge
touches the head or tail node, respectively. Note that this only
specifies the shape. The dir attribute determines whether or not the
glyph is drawn.

arrowsize=val specifies a multiplicative scale factor for the size of
the arrowhead. inv_length=6,inv_width=7,dot_radius=2)

headlabel,taillabel=text for labels appearing near the head and tail
nodes of an edge. labelfontcolor, labelfontname, labelfontsize for
head and tail labels. The substrings '\T', '\H', '\E' and '\G' are
substituted in the same manner as for the edge label attribute.
Additionally the substring '\L' is substituted with the edge label
string.

headhref="url" sets the url for the head port in imagemap, PostScript
and SVG files. The substrings '\T', '\H', '\E' and '\G' are
substituted in the same manner as for the edge label attribute.
Additionally the substring '\L' is substituted with the edge label
string.

headURL="url" (headURL is a synonym for headhref.)

headtarget="headtarget" is a target string for client-side imagemaps
and SVG, effective when edge heads have a URL. The headtarget string
is used to determine which window of the browser is used for the URL.
If the headtarget string is empty, the default, then headtarget
defaults to the same value as target for the edge. The substrings
'\T', '\H', '\E' and '\G' are substituted in the same manner as for
the edge label attribute. Additionally the substring '\L' is
substituted with the edge label string.

headtooltip="tooltip" is a tooltip string for client-side imagemaps
effective when head ports have a URL. The tooltip string defaults to
be the same as the headlabel string. The substrings '\T', '\H', and
'\E' are substituted in the same manner as for the edge label
attribute. Additionally the substring '\L' is substituted with the
edge label string.

tailhref="url" sets the url for the tail port in imagemap, PostScript
and SVG files. The substrings '\T', '\H', '\E' and '\G' are
substituted in the same manner as for the edge label attribute.
Additionally the substring '\L' is substituted with the edge label
string.

tailURL="url" (tailURL is a synonym for tailhref.)

tailtarget="tailtarget" is a target string for client-side imagemaps
and SVG, effective when edge tails have a URL. The tailtarget string
is used to determine which window of the browser is used for the URL.
If the tailtarget string is empty, the default, then tailtarget
defaults to the same value as target for the edge. The substrings
'\T', '\H', '\E' and '\G' are substituted in the same manner as for
the edge label attribute. Additionally the substring '\L' is
substituted with the edge label string.

tailtooltip="tooltip" is a tooltip string for client-side imagemaps
effective when tail ports have a URL. The tooltip string defaults to
be the same as the taillabel string. The substrings '\T', '\H', '\E'
and '\G' are substituted in the same manner as for the edge label
attribute. Additionally the substring '\L' is substituted with the
edge label string.

labeldistance and labelangle (in degrees CCW) specify the placement
of head and tail labels.

decorate draws line from edge to label.

samehead,sametail aim edges having the same value to the same port,
using the average landing point.

(dot-specific attributes)
constraint=false causes an edge to be ignored for rank assignment.

minlen=n where n is an integer factor that applies to the edge length
(ranks for normal edges, or minimum node separation for flat edges).

xlabel="text" Edge labels in dot are treated as special types of
nodes, with space allocated for them during node layout. This can
sometimes deform the edge routing. If an xlabel is used instead, the
label is placed after all nodes and edges have been positioned. In
turn, this may mean that there is some overlap among the labels.

(neato and fdp-specific attributes)
len=f sets the optimal length of an edge. The default is 1.0.

COMMAND-LINE OPTIONS
-G sets a default graph attribute.
-N sets a default node attribute.
-E sets a default edge attribute. Example: -Gsize="7,8" -Nshape=box
-Efontsize=8

--filepath=path uses path as a prefix for locating externally
referenced files. For example, using --filepath=bar/baz would cause
foo.png in image="foo.png" to be looked for on disk as
bar/baz/foo.png. This overrides any imagepath set either on the
command line or as an attribute within the input graph source.

-lfile loads custom PostScript library files. Usually these define
custom shapes or styles. If -l is given by itself, the standard
library is omitted.

-Tlang sets the output language as described above.

-n[1|2] (no-op) If set, neato assumes nodes have already been
positioned and all nodes have a pos attribute giving the positions.
It then performs an optional adjustment to remove node-node overlap,
depending on the value of the overlap attribute, computes the edge
layouts, depending on the value of the splines attribute, and emits
the graph in the appropriate format. If num is supplied, the
following actions occur:
num = 1
Equivalent to -n.
num > 1
Use node positions as specified, with no adjustment to remove
node-node overlaps, and use any edge layouts already specified by the
pos attribute. neato computes an edge layout for any edge that does
not have a pos attribute. As usual, edge layout is guided by the
splines attribute.

-Klayout override the default layout engine implied by the command
name.

-O automatically generate output filenames based on the input
filename and the -T format.

-P generate a graph of the currently available plugins.

-v (verbose) prints various information useful for debugging.

-c configure plugins.

-qlevel set level of message suppression. The default is 1.

-sfscale scale input by fscale, the default is 72.

-y invert y coordinate in output.

-ofile write output to file.

-x reduce graph.

-Lg don't use grid.

-LO use old attractive force.

-Lni set number of iterations to i.

-LUi set unscaled factor to i.

-LCv set overlap expansion factor to v.

-LT[*]v set temperature (temperature factor) to v.

-V (version) prints version information and exits.

-? prints the usage and exits.

A complete description of the available command-line options can be
found at https://www.graphviz.org/doc/info/command.html.

EXAMPLES

digraph test123 {
a -> b -> c;
a -> {x y};
b [shape=box];
c [label="hello\nworld",color=blue,fontsize=24,
fontname="Palatino-Italic",fontcolor=red,style=filled];
a -> z [label="hi", weight=100];
x -> z [label="multi-line\nlabel"];
edge [style=dashed,color=red];
b -> x;
{rank=same; b x}
}

graph test123 {
a -- b -- c;
a -- {x y};
x -- c [w=10.0];
x -- y [w=5.0,len=3];
}

CAVEATS

Edge splines can overlap unintentionally.

Flat edge labels are slightly broken. Intercluster edge labels are
totally broken.

Because unconstrained optimization is employed, node boxes can
possibly overlap or touch unrelated edges. All existing spring
embedders seem to have this limitation.

Apparently reasonable attempts to pin nodes or adjust edge lengths
and weights can cause instability.

AUTHORS

Stephen C. North <north@research.att.com>
Emden R. Gansner <erg@graphviz.org>
John C. Ellson <ellson@research.att.com>
Yifan Hu <yifanhu@yahoo.com>

The bitmap driver (PNG, GIF etc) is by Thomas Boutell,
<http://www.boutell.com/gd>

The Truetype font renderer is from the Freetype Project (David
Turner, Robert Wilhelm, and Werner Lemberg) (who can be contacted at
freetype-devel@lists.lrz-muenchen.de).

NOTES

On non-Windows platforms, sending SIGUSR1 to Graphviz can be used to
toggle on and off some extra points reporting in the neatogen code.

12 January 2015 DOT(1)