DOT(1)

NAME
dot - preprocessor for drawing directed graphs

SYNOPSIS
dot [-Gname=value] [-Nname=value] [-Ename=value] [-Tlang] [-l libfile] [-o outfile] [files]

DESCRIPTION
dot draws directed graphs. It works well on DAGs and other graphs that can be drawn as hierarchies. It reads attributed graph files and writes drawings. By default, the output format dot is the input file with layout coordinates appended. To generate PostScript, use the -Tps option. Other choices are -Tmif (FrameMaker graphics), -Thpgl (HP pen plotters), and -Tpcl (Laserjet printers), -Tgif (pixel graphics), -Timap, and -Tismap (imagemap files for httpd servers that mark out rectangles for each node that has a non-null URL attribute.).

Here is a synopsis of the graph file language.

digraph name { statement-list } is the top level graph. 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 -> n1 -> ... -> 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.

GRAPH ATTRIBUTES

size="x,y" sets bounding box of drawing in inches.

page="x,y" sets the PostScript pagination unit.

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

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 requests a left-to-right drawing.

pagedir=[TBLR][TBLR] sets the major and minor order of pagination.

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.

nslimit=f or mclimit=f adjusts the bound on the number of network simplex or mincross iterations by the given ratio. For example, mclimit=2.0 runs twice as long.

layers="id:id:id:id" is a sequence of layer identifiers for overlay diagrams. The PostScript array variable layercolorseq sets the assignment of colors to layers. The least index is 1 and each element must be a 3-element array to be interpreted as a color coordinate.

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

URL="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.

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_polygon
builtin_polygon is one of: plaintext ellipse circle egg triangle box diamond trapezium parallelogram house hexagon octagon. (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.

label=text where text may include escaped newlines \n, \l, or \r for center, left, and right justified lines. 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).

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.

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

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 supercedes 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.

URL="url" sets the url for the node in image map and PostScript files. The string '\N' value will be replaced by the node name. In PostScript files, URL information is embedded in such a way that Acrobat Distiller creates PDF files with active hyperlinks.

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.

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.

dir=forward back both none controls arrow direction.

tailclip,headclip=false disables endpoint shape clipping.

arrowhead,arrowtail=none,normal,inv,dot,odot,invdot,invodot.

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.

labeldistance and port_label_distance set distance; also labelangle (in degrees CCW) .PP decorateP 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 edgess active layers. The empty string means no layers (invisible).

OPTIONS
-G sets a default graph attribute. -N and -E set default attributes for nodes and edges. Some examples: -Gsize="7,8" or -Nshape=box or -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.

EXAMPLE
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}
}

BUGS
Edge splines can overlap unintentionally.

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

SEE ALSO

dotty(1)
neato(1)
tcldot(n)
xcolors(1)
libgraph(3)

E. R. Gansner, S. C. North, K. P. Vo, "DAG — A Program to Draw Directed Graphs", Software — Practice and Experience 17(1), 1988, pp. 1047-1062.
E. R. Gansner, E. Koutsofios, S. C. North, K. P. Vo, "A Technique for Drawing Directed Graphs," IEEE Trans. on Soft. Eng. 19(3), 1993, pp. 214-230.
S. North and E. Koutsofios, "Applications of graph visualization", Graphics Interface 94, pp. 234-245.
E. Koutsofios and S. C. North, "Drawing Graphs with dot," Available on research.att.com in dist/drawdag/dotguide.ps.Z.
The GIF driver is a publically available library from the Quest Center at Cold Spring Harbor Labs (courtesy Tom Boutell, boutell@netcom.com). The Truetype font renderer for the GIF driver was written by the Freetype Project (David Turner, Robert Wilhelm, and Werner Lemberg) (who can be contacted at freetype-devel@lists.lrz-muenchen.de).