


DOT(1)                                                     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  cir-
       cle.  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.



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DOT(1)                                                     DOT(1)


       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 follow-
       ing sections describe attributes that control graph layout.




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DOT(1)                                                     DOT(1)


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 num-
       ber, 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 compati-
       ble 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  sim-
       plex   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 assign-
       ment 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)



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DOT(1)                                                     DOT(1)


       start=val.  Requests random initial placement and seeds the random num-
       ber  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 lay-
       out. 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 uni-
       formly 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  seg-
       ments 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  seg-
       ments 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.




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DOT(1)                                                     DOT(1)


       start=val. Adjusts the random initial placement of nodes with no speci-
       fied 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 fixed-
       size=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:



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DOT(1)                                                     DOT(1)


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

       peripheries=n sets the number of periphery lines drawn around the poly-
       gon.   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-dis-
       placement 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 deter-
       mine 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 with-
       out  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



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DOT(1)                                                     DOT(1)


       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  posi-
       tion.


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 order-
       ing 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  paral-
       lel 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 sub-
       strings '\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



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DOT(1)                                                     DOT(1)


       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,labelfont-
       name,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.



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DOT(1)                                                     DOT(1)


       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 posi-
       tioned 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 lay-
       outs,  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.



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DOT(1)                                                     DOT(1)


       -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



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DOT(1)                                                     DOT(1)


       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.



































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