DOT(1)                     OpenBSD Reference Manual                     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

SYNOPSIS
       dot [-(G|N|E)name=value] [-Tlang] [-l libfile] [-o outfile] [-v] [-V]
       [files]
       neato [-(G|N|E)name=value] [-Tlang] [-l libfile] [-n[1|2]] [-o outfile]
       [-v] [-V] [files]
       twopi [-(G|N|E)name=value] [-Tlang] [-l libfile] [-o outfile] [-v] [-V]
       [files]
       circo [-(G|N|E)name=value] [-Tlang] [-l libfile] [-o outfile] [-v] [-V]
       [files]
       fdp [-(G|N|E)name=value] [-Tlang] [-l libfile] [-o outfile] [-v] [-V]
       [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.

       neato draws undirected graphs using ``spring'' models (see Kamada and
       Kawai, Information Processing Letters 31:1, April 1989).  Input files
       must be formatted in the dot attributed graph language.  By default,
       the output of neato is the input graph with layout coordinates
       appended.

       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).

OUTPUT FORMATS
       Dot 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, dot supports the following: -Tps (PostScript), -Tsvg
       -Tsvgz (Structured Vector Graphics), -Tfig (XFIG graphics), -Tmif
       (FrameMaker graphics), -Thpgl (HP pen plotters), and -Tpcl (Laserjet
       printers), -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/cvs/doc/info/output.html.)

GRAPH FILE LANGUAGE
       Here is a synopsis of the graph file language, traditionally using the
       extension .dot, 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.


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|RL|BT requests a left-to-right, right-to-left, or bottom-to-
       top, 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).

       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.


       (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.

       splines=boolean. Setting this to true causes edges to be drawn as
       splines if nodes don't overlap. The default is false.


       (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.

       splines=true/false. If set to true, twopi will use the graphviz path
       planning library to draw edges as splines avoiding nodes.  If the value
       is false, or some nodes overlap, edges are drawn as straight line
       segments connecting nodes.  This is also the default style.


       (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.

       splines=true/false. If set to true, circo will use the graphviz path
       planning library to draw edges as splines avoiding nodes.  If the value
       is false, or some nodes overlap, edges are drawn as straight line
       segments connecting nodes.  This is also the default style.


       (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.

       splines=val. If val is "true", edges are drawn as splines to avoid
       nodes. By default, edges are draw as line segments.

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 oval 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.  The string '\N' value will be
       replaced by the node 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).

       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 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.

       href="url" sets the url for the node in imagemap, PostScript and SVG
       files.  The substring '\N' is substituted in the same manner as for the
       node label attribute.

       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 substring '\N' is
       substituted in the same manner as for the node label attribute.

       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 substring '\N' is substituted in the same manner as for the node
       label attribute.


       (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 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', and '\E' are substituted in the same
       manner as for the edge label attribute.

       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', and '\E' are substituted in the same manner as
       for the edge label attribute.

       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', and '\E' are
       substituted in the same manner as for the edge label attribute.

       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', and '\E' are substituted in the same manner
       as for the edge label attribute.

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

       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', and '\E' are substituted in the same manner as for the edge
       label attribute.

       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.

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

       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', and '\E' are substituted in the same manner as for the edge
       label attribute.

       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', and
       '\E' are substituted in the same manner as for the edge label
       attribute.

       labeldistance and port_label_distance set distance; also labelangle (in
       degrees CCW)

       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 edgess 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.

       -v (verbose) prints delta energy every 100th iteration.

       -V (version) prints version information and exits.

       -? prints the usage and exits.

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@research.att.com>
       John C. Ellson <ellson@research.att.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).

SEE ALSO
       This man page contains only a small amount of the information related
       to the Graphviz layout programs. The most complete information can be
       found at http://www.graphviz.org/Documentation.php, especially in the
       on-line reference pages. Most of these documents are also available in
       the doc and doc/info subtrees in the source and binary distributions.

       dotty(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.
       S. C. North, "NEATO User's Manual".  Available on research.att.com in
       dist/drawdag/neatodoc.ps.Z.



                                23 August 2004                          DOT(1)
