neato - Online in the Cloud

PROGRAM:

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 tree maps

SYNOPSIS

dot [options] [files]
neato [options] [files]
twopi [options] [files]
circle [options] [files]
fdp [options] [files]
sfdp [options] [files]
patchwork [options] [files]

DESCRIPTION

These are a collection of programs for drawing graphs. There is actually only one main
program; the specific layout algorithms implemented as plugins. Thus, they largely share
all of the same command-line options. dot draws directed graphs. It works well on DAGs
and other graphs that can be drawn as hierarchies.

neato draws undirected graphs using ``spring'' models (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.

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 -Txxx'' (where xxx is
an unlikely format) and check the warning message. Also, The plugin mechanism supports
multiple implementations of the output formats. To see what variants are available, use,
for example: ``dot -Tpng:'' and to force a particular variant, use, for example: ``dot
-Tpng:gd''

Traditionally, Graphviz supports the following:
-Tps (PostScript),
-Tsvg -Tsvgz (Structured Vector Graphics),
-Tfig (XFIG graphics),
-Tpng -Tgif (bitmap graphics),
-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
//http://www.graphviz.org/content/output-formats.

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.

Comments may be /*C‐like*/ or //C++‐like.

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
http://www.graphviz.org/content/dot-language.

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 http://www.graphviz.org/content/attrs.

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).

nodesep=f sets the minimum separation between nodes.

ranksep=f sets the minimum separation between ranks.

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

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.

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).

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".)

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 may 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.

(neato‐specific attributes)
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.

overlap=mode. This specifies what twopi should do if any nodes overlap. If mode is
"false", the program uses Voronoi diagrams 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.

(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 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=record polygon epsf builtin_shape
builtin_polygon can be plaintext ellipse oval circle egg triangle box diamond trapezium
parallelogram house hexagon octagon note tab box3d 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 http://www.graphviz.org/content/node-shapes for a complete description of node shapes.

label=text where text may include escaped newlines \n, \l, or \r for center, left, and
right justified lines. The string '\N' value will be replaced by the node name. The
string '\G' value will be replaced by the graph name. Record labels may contain recursive
box lists delimited by { | }. Port identifiers in labels are set off by angle brackets <
>. In the graph file, use colon (such as, node0:port28).

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

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

fontname=name sets the label font family name.

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.

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 cyan or
burlywood, or a "#rrggbb" (red, green, blue, 2 hex characters each) value.

style=filled solid dashed dotted bold invis or any Postscript code.

href="url" sets the url for the node in imagemap, PostScript and SVG files. 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.

URL="url" ("URL" is a synonym for "href".)

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="tooltip" 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.

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

Edge Attributes
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).

weight=n where n is the integer cost of the edge. Values greater than 1 tend to shorten
the edge. Weight 0 flat edges are ignored for ordering nodes.

label=text where text may include escaped newlines \n, \l, or \r for centered, left, or
right justified lines. If the substring '\T' is found in a label it will be replaced by
the tail_node name. If the substring '\H' is found in a label it will be replaced by the
head_node name. If the substring '\E' value is found in a label it will be replaced by:
tail_node_name->head_node_name If the substring '\G' is found in a label it will be
replaced by the graph name. or by: tail_node_name--head_node_name for undirected graphs.

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

fontname=name sets the label font family name.

fontcolor=colorvalue sets the label text color.

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.

href="url" sets the url for the node 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.

URL="url" ("URL" is a synonym for "href".)

target="target" 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="tooltip" 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.

arrowsize (norm_length=10,norm_width=5, inv_length=6,inv_width=7,dot_radius=2)

headlabel,taillabel=string for port labels. 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.

constraint=false causes an edge to be ignored for rank assignment.

layer=id or id:id or "all" sets the edge's active layers. The empty string means no
layers (invisible).

(neato‐specific attributes)
w=f sets the weight (spring constant) of an edge to the given floating point value. The
default is 1.0; greater values make the edge tend more toward its optimal length.

len=f sets the optimal length of an edge. The default is 1.0.

(fdp‐specific attributes)
weight=f sets the weight of an edge to the given floating point value. The default is 1.0;
greater values make the edge tend more toward its optimal length.

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

-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.

-m memory test (observe no growth with top, kill when done).

-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.

-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
http://www.graphviz.org/content/command-line-invocation.

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 <[email protected]>
Emden R. Gansner <[email protected]>
John C. Ellson <[email protected]>
Yifan Hu <[email protected]>

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 [email protected]).

Use neato online using onworks.net services