All Graphviz attributes are specified by name-value pairs. Thus, to
set the fillcolor of a node abc, one would use
- Damping
- Factor damping force motions. On each iteration, a nodes movement
is limited to this factor of its potential motion. By being less than
1.0, the system tends to ``cool'', thereby preventing cycling.
- URL
- Hyperlinks incorporated into device-dependent output.
At present, used in ps2, cmap, i*map and svg formats.
For all these formats, URLs can be attached to nodes, edges and
clusters. URL attributes can also be attached to the root graph in ps2,
cmap and i*map formats. This serves as the base URL for relative URLs in the
former, and as the default image map file in the latter.
The active area for a node or cluster is its bounding box. For edges,
the active areas are small circles where the edge contacts its head
and tail nodes. These areas may overlap the related node, and the edge
URL dominates.
If the edge has a label, this will also be active.
Finally, if the edge has a head or tail label, this will also be active.
Note, however, that if the edge has a headURL
attribute, it is this value that is used near the head node and on
the head label, if defined. The similar restriction holds when
tailURL is defined.
The URL of the root graph is only treated as an
escString if the output format is cmap.
- arrowhead
- Style of arrowhead on the head node of an edge.
See also the dir attribute,
and a limitation.
- arrowsize
- Multiplicative scale factor for arrowheads.
- arrowtail
- Style of arrowhead on the tail node of an edge.
See also the dir attribute,
and a limitation.
- bb
- Bounding box of drawing in integer points.
- bgcolor
- When attached to the root graph, this color is used as the background for
entire canvas. When a cluster attribute, it is used as the initial
background for the cluster. If a cluster has a filled
style, the
cluster's fillcolor will overlay the
background color.
If no background color is specified for the root graph, no graphics
operation are performed on the background. This works fine for
PostScript but for bitmap output, all bits are initialized to something.
This means that when the bitmap output is included in some other
document, all of the bits within the bitmap's bounding box will be
set, overwriting whatever color or graphics where already on the page.
If this effect is not desired, and you only want to set bits explicitly
assigned in drawing the graph, set background="transparent".
- center
- If true, the drawing is centered in the output canvas.
- clusterrank
- Mode used for handling clusters. If clusterrank is "local", a
subgraph whose name begins with "cluster" is given special treatment.
The subgraph is laid out separately, and then integrated as a unit into
its parent graph, with a bounding rectangle drawn about it.
If the cluster has a label parameter, this label
is displayed within the rectangle.
Note also that there can be clusters within clusters.
At present, the modes "global" and "none"
appear to be identical, both turning off the special cluster processing.
- color
- Basic drawing color for graphics, not text. For the latter, use the
fontcolor attribute. For edges, the value
can either be a single color or a colorList.
In the latter case, the edge is drawn using parallel splines or lines,
one for each color in the list, in the order given.
- comment
- Comments are inserted into output. Device-dependent
- compound
- If true, allow edges between clusters. (See lhead
and ltail below.)
- concentrate
- If true, use edge concentrators.
- constraint
- If false, the edge is not used in ranking the nodes. For example,
in the graph
digraph G {
a -> c;
a -> b;
b -> c [constraint=false];
}
the edge b -> c does not add a constraint during rank
assignment, so the only constraints are that a be above b and c,
yielding the graph:
- decorate
- If true, attach edge label to edge by a 2-segment
polyline, underlining the label, then going to the closest point of spline.
- defaultdist
- This specifies the distance between nodes in separate connected
components. If set too small, connected components may overlap.
Only applicable if pack=false.
- dim
- Set the number of dimensions used for the layout. The maximum value
allowed is 10.
- dir
- Set edge type for drawing arrowheads. This indicates which ends of the
edge should be decorated with an arrowhead. The actual style of the
arrowhead can be specified using the arrowhead
and arrowtail attributes.
See limitation.
- distortion
- Distortion factor for shape=polygon.
Positive values cause top part to
be larger than bottom; negative values do the opposite.
- dpi
- This specifies the expected number of pixels per inch on a display device.
For bitmap output, this guarantees that text rendering will be
done more accurately, both in size and in placement. For SVG output,
it is used to guarantee that the dimensions in the output correspond to
the correct number of points or inches.
- epsilon
- Terminating condition. If the length squared of all energy gradients are
< epsilon, the algorithm stops.
- fillcolor
- Color used to fill the background of a node or cluster.
If fillcolor is not defined, color is
used. (For clusters, if color is not defined,
bgcolor is used.) If this is not defined,
the default is used, except for
shape=point or when the output
format is MIF,
which use black by default.
Note that a cluster inherits the root graph's attributes if defined.
Thus, if the root graph has defined a fillcolor, this will override a
color or bgcolor attribute set for the cluster.
- fixedsize
- If true, the node size is specified by the values of the
width
and height attributes only
and is not expanded to contain the text label.
- fontcolor
- Color used for text.
- fontname
- Font used for text. This very much depends on the output format and, for
non-bitmap output such as PostScript or SVG, the availability of the font
when the graph is displayed or printed. As such, it is best to rely on
font faces that are generally available, such as Times-Roman, Helvetica or
Courier.
If Graphviz was built using the
fontconfig library, the latter library
will be used to search for the font. However, if the fontname string
contains a slash character "/", it is treated as a pathname for the font
file, though font lookup will append the usual font suffixes.
If Graphviz does not use fontconfig, fontname will be
considered the name of a Type 1 or True Type font file.
If you specify fontname=schlbk, the tool will look for a
file named schlbk.ttf or schlbk.pfa or schlbk.pfb
in one of the directories specified by
the fontpath attribute.
The lookup does support various aliases for the common fonts.
- fontpath
- Directory list used by libgd to search for bitmap fonts if Graphviz
was not built with the fontconfig library.
If fontpath is not set, the environment
variable DOTFONTPATH is checked.
If that is not set, GDFONTPATH is checked.
If not set, libgd uses its compiled-in font path.
Note that fontpath is an attribute of the root graph.
- fontsize
- Font size, in points, used for text.
- group
- If the end points of an edge belong to the same group, i.e., have the
same group attribute, parameters are set to avoid crossings and keep
the edges straight.
- headURL
- For the output format imap or cmap, if headURL is defined, it is
output as part of the head label of the edge.
See limitation.
- headclip
- If true, the head of an edge is clipped to the boundary of the head node;
otherwise, the end of the edge goes to the center of the node, or the
center of a port, if applicable.
- headhref
- Synonym for headURL.
- headlabel
- Text label to be placed near head of edge.
See limitation.
- headport
- Indicates where on the head node to attach the head of the edge.
In the default case, the edge is aimed towards the center of the node,
and then clipped at the node boundary.
See limitation.
- headtarget
- If the edge has a headURL,
this attribute determines 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 undefined, the value of the target is used.
- headtooltip
- Tooltip annotation attached to the head of an edge. This is used only
if the edge has a headURL attribute.
- height
- Height of node, in inches. This is taken as the initial, minimum height
of the node. If fixedsize is true, this
will be the final height of the node. Otherwise, if the node label
requires more height to fit, the node's height will be increased to
contain the label. Note also that, if the output format is dot, the
value given to height will be the final value.
- href
- Synonym for URL.
- label
- Text label attached to objects.
If a node's shape is record, then the label can
have a special format
which describes the record layout.
- labelangle
- This, along with labeldistance, determine
where the
headlabel (taillabel) are placed with respect to the head (tail)
in polar coordinates. The origin in the coordinate system is
the point where the edge touches the node. The ray of 0 degrees
goes from the origin back along the edge, parallel to the edge
at the origin.
The angle, in degrees, specifies the rotation from the 0 degree ray,
with positive angles moving counterclockwise and negative angles
moving clockwise.
- labeldistance
- Multiplicative scaling factor adjusting the distance that
the headlabel(taillabel) is from the head(tail) node.
The default distance is 10 points. See labelangle
for more details.
- labelfloat
- If true, allows edge labels to be less constrained in position.
In particular, it may appear on top of other edges.
- labelfontcolor
- Color used for headlabel and taillabel.
If not set, defaults to edge's fontcolor.
- labelfontname
- Font used for headlabel and taillabel.
If not set, defaults to edge's fontname.
- labelfontsize
- Font size, in points, used for headlabel and taillabel.
If not set, defaults to edge's fontsize.
- labeljust
- Justification for cluster labels. If "r", the label
is right-justified within bounding rectangle; if "l", left-justified;
else the label is centered.
Note that a subgraph inherits attributes from its parent. Thus, if
the root graph sets labeljust to "l", the subgraph inherits
this value.
- labelloc
- Top/bottom placement of graph and cluster labels.
If the attribute is "t", place label at the top;
if the attribute is "b", place label at the bottom.
By default, root
graph labels go on the bottom and cluster labels go on the top.
Note that a subgraph inherits attributes from its parent. Thus, if
the root graph sets labelloc to "b", the subgraph inherits
this value.
- layer
- Specifies layers in which the node or edge is present.
- layers
- Specifies a linearly ordered list of layer names attached to the graph
The graph is then output in separate layers. Only those components
belonging to the current output layer appear. For more information,
see the page How to use drawing layers (overlays).
- layersep
- Specifies the separator characters used to split the
layers attribute into a list of layer names.
- len
- Preferred edge length, in inches.
- lhead
- Logical head of an edge. When compound is true,
if lhead is defined and is the name of a cluster containing
the real head,
the edge is clipped to the boundary of the cluster.
See limitation.
- lp
- Label position, in points.
- ltail
- Logical tail of an edge. When compound is true,
if ltail is defined and is the name of a cluster
containing the real tail,
the edge is clipped to the boundary of the cluster.
See limitation.
- margin
- For graphs, this sets x and y margins of canvas, in inches. If the margin
is a single double, both margins are set equal to the given value.
For nodes, this attribute specifies space left around the node's label.
By default, the value is 0.11,0.055.
- maxiter
- Sets the number of iterations used.
- mclimit
- Multiplicative scale factor used to alter the MinQuit (default = 8)
and MaxIter (default = 24) parameters used during crossing
minimization. These correspond to the
number of tries without improvement before quitting and the
maximum number of iterations in each pass.
- mindist
- Specifies the minimum separation between all nodes.
- minlen
- Minimum edge length (rank difference between head and tail).
- mode
- Technique for optimizing the layout. If mode is "major",
neato uses stress majorization. If mode is "KK",
neato uses a version of the gradient descent method. The only advantage
to the latter technique is that it is sometimes appreciably faster for
small (number of nodes < 100) graphs. A significant disadvantage is that
it may cycle.
- model
- This value specifies how the distance matrix is computed for the input
graph. The distance matrix specifies the ideal distance between every
pair of nodes. neato attemps to find a layout which best achieves
these distances. By default, it uses the length of the shortest path,
where the length of each edge is given by its len
attribute. If model is "circuit", neato uses the
circuit resistance
model to compute the distances. This tends to emphasize clusters. If
model is "subset", neato uses the subset model. This sets the
edge length to be the number of nodes that are neighbors of exactly one
of the end points, and then calculates the shortest paths. This helps
to separate nodes with high degree.
- nodesep
- Minimum space between two adjacent nodes in the same rank, in inches.
- nojustify
- By default, the justification of multi-line labels is done within the
largest context that makes sense. Thus, in the label of a polygonal
node, a left-justified line will align with the left side of the node
(shifted by the prescribed margin).
In record nodes, left-justified
line will line up with the left side of the enclosing column of fields.
If nojustify is "true", multi-line labels will be justified
in the context of itself. For example, if the attribute is set,
the first label line is long, and the second is shorter and left-justified,
the second will align with the left-most character in the first line,
regardless of how large the node might be.
- normalize
- If set, normalize coordinates of final
layout so that the first point is at the origin, and then rotate the
layout so that the first edge is horizontal.
- nslimit
,
- nslimit1
- Used to set number of iterations in
network simplex applications. nslimit is used in
computing node x coordinates, nslimit1 for ranking nodes.
If defined, # iterations = nslimit(1) * # nodes;
otherwise, # iterations = MAXINT.
- ordering
- If "out" for a graph G, and n is a node in G, then edges n->* appear
left-to-right in the same order in which they are defined.
If "in", the edges *->n appear
left-to-right in the same order in which they are defined for all
nodes n.
- orientation
- Angle, in degrees, used to rotate node shapes.
- orientation
- If "[lL]*", set graph orientation to landscape
Used only if rotate is not defined.
- outputorder
- Specify order in which nodes and edges are drawn.
- overlap
- Determines if and how node overlaps should be removed. If "true"
(the default), overlaps are retained.
If the value is "scale", overlaps are removed by uniformly scaling in x and y.
If the value converts to "false", node overlaps are removed by a
Voronoi-based technique. If the value is "scalexy", x and y are separately
scaled to remove overlaps. If the value is "orthoxy" or "orthoyx", overlaps
are moved by optimizing two constraint problems, one for the x axis and
one for the y. The suffix indicates which axis is processed first.
If the value is "compress", the layout will be scaled down as much as
possible without introducing any overlaps.
Except for the Voronoi method, all of these transforms preserve the
orthogonal ordering of the original layout. That is, if the x coordinates
of two nodes are originally the same, they will remain the same, and if
the x coordinate of one node is originally less than the x coordinate of
another, this relation will still hold in the transformed layout. The
similar properties hold for the y coordinates.
NOTEThe methods related to "orthoxy" and "orthoyx" are still evolving. The
semantics of these may change, or these methods may disappear altogether.
- pack
- This is true if the value of pack is "true" (case-insensitive) or a
non-negative integer. If true, each connected component of the graph is
laid out separately, and then the graphs are packed tightly.
If pack has an integral value, this is used as the size (in points) of
a margin around each part; otherwise, a default margin of 8 is used.
If pack is interpreted as false, the entire graph is laid out together.
The granularity and method of packing is influenced by the
packmode attribute.
For layouts which always do packing, such a twopi, the pack
attribute is just used to set the margin.
- packmode
- This indicates the granularity and method used for packing
(cf. packMode). Note that defining
packmode will automatically turn on packing as though one had
set pack=true.
- page
- Width and height of output pages, in inches. If this is set and is
smaller than the size of the layout, a rectangular array of pages of
the specified page size is overlaid on the layout, with origins
aligned in the lower-left corner, thereby partitioning the layout
into pages. The pages are then produced one at a time, in
pagedir order.
- pagedir
- If the page attribute is set and applicable,
this attribute specifies the order in which the pages are emitted.
This is limited to one of the 8 row or column major orders.
- pencolor
- Color used to draw the bounding box around a cluster.
If pencolor is not defined, color is
used. If this is not defined, bgcolor is used.
If this is not defined, the default is used.
Note that a cluster inherits the root graph's attributes if defined.
Thus, if the root graph has defined a pencolor, this will override a
color or bgcolor attribute set for the cluster.
- peripheries
- Set number of peripheries used in polygonal shapes and cluster
boundaries. Note that
user-defined shapes are treated as a
form of box shape, so the default
peripheries value is 1 and the user-defined shape will be drawn in
a bounding rectangle. Setting peripheries=0 will turn this off.
Also, 1 is the maximum peripheries value for clusters.
- pin
- If true and the node has a pos attribute on input, neato prevents the
node from moving from the input position. This property can also be specified
in the pos attribute itself (cf. the point type).
- pos
- Position of node, or spline control points, in points.
In neato and fdp, pos can be used to set initial position of a node.
Concerning this, see the -s command line flag.
- quantum
- If quantum > 0.0, node label dimensions
will be rounded to integral multiples of the quantum.
- rank
- Rank constraints on the nodes in a subgraph.
If rank="same", all nodes are placed on the same rank.
If rank="min", all nodes are placed on the minimum rank.
If rank="source", all nodes are placed on the minimum rank, and
the only nodes on the minimum rank belong to some subgraph whose
rank attribute is "source" or "min".
Analogous criteria hold for rank="max" and rank="sink".
(Note: the
minimum rank is topmost or leftmost, and the maximum rank is bottommost
or rightmost.)
- rankdir
- Sets direction of graph layout. For example, if rankdir="LR",
and barring cycles, an edge
T -> H; will go
from left to right. By default, graphs are laid out from top to bottom.
- ranksep
- In dot, this the gives desired rank separation, in inches. This is
the minimum vertical distance between the bottom of the nodes in one
rank and the tops of nodes in the next. If the value
contains "equally", the centers of all ranks are spaced equally apart.
Note that both
settings are possible, e.g., ranksep = "1.2 equally".
In twopi, specifies radial separation of concentric circles.
- ratio
- Sets the aspect ratio (drawing height/drawing width) for the drawing.
Note that this is adjusted before
the size attribute constraints are enforced.
If ratio is numeric, it is taken as the desired aspect ratio.
Then, if the actual aspect ratio is less than the desired ratio,
the drawing height is scaled up to achieve the
desired ratio; if the actual ratio is greater than that desired ratio,
the drawing width is scaled up.
If ratio = "fill" and the size
attribute is set, node positions are scaled, separately in both x
and y, so that the final drawing exactly fills the specified size.
If ratio = "compress" and the size
attribute is set, dot attempts to compress the initial layout to fit
in the given size. This achieves a tighter packing of nodes but
reduces the balance and symmetry. This feature only works in dot.
If ratio = "expand", the size
attribute is set, and both the width and the height of the graph are
less than the value in size, node positions are scaled
uniformly until at least
one dimension fits size exactly.
Note that this is distinct from using size as the
desired size, as here the drawing is expanded before edges are generated and
all node and text sizes remain unchanged.
If ratio = "auto", the page
attribute is set and the graph cannot be drawn on a single page,
then size is set to an ``ideal'' value.
In particular, the size in a given dimension will be the smallest integral
multiple of the page size in that dimension which is at least half the
current size. The two dimensions are then scaled independently to the
new size. This feature only works in dot.
- rects
- Rectangles for fields of records, in points.
- regular
- If true, force polygon to be regular.
- remincross
- If true and there are multiple clusters, run cross
minimization a second time.
- resolution
- This is a synonym for the dpi attribute.
- root
- This specifies nodes to be used as the center of the
layout and the root of the generated spanning tree. As a graph attribute,
this gives the name of the node. As a node attribute (circo only), it
specifies that the node should be used as a central node. In twopi,
this will actually be the central node. In circo, the block containing
the node will be central in the drawing of its connected component.
If not defined,
twopi will pick a most central node, and circo will pick a random node.
- rotate
- If 90, set drawing orientation to landscape.
- samehead
- Edges with the same head and the same samehead value are aimed
at the same point on the head.
See limitation.
- sametail
- Edges with the same tail and the same sametail value are aimed
at the same point on the tail.
See limitation.
- samplepoints
- If the input graph defines the vertices
attribute, and output is dot or xdot, this give
the number of points used to represent circles and ellipses.
It plays the same role in neato, when adjusting the layout to avoid
overlapping nodes.
- searchsize
- During network simplex, maximum number of edges with negative cut values
to search when looking for one with minimum cut value.
- sep
- Fraction to increase polygons (multiply
coordinates by 1 + sep) for purposes of determining overlap. Guarantees
a minimal non-zero distance between nodes.
- shape
- Set the shape of a node.
- shapefile
- If defined, shapefile specifies a file containing user-supplied node content.
The shape of the node is set to box.
The image in the shapefile must be
rectangular. The image formats supported as well as the precise semantics of
how the file is used depends on the
output format. For further details, see
External PostScript files.
There is one exception to this usage.
If shape is set to "epsf", shapefile gives
a filename containing a definition of the node in PostScript.
The graphics defined must be contain all of the
node content, including any desired boundaries.
For further details, see
External PostScript files.
- showboxes
- Print guide boxes in PostScript at the beginning of
routesplines if 1, or at the end if 2. (Debugging)
- sides
- Number of sides if shape=polygon.
- size
- Maximum width and height of drawing, in inches.
If defined and the drawing is too large, the drawing is uniformly
scaled down so that it fits within the given size.
If size ends in an exclamation point (!),
then it is taken to be
the desired size. In this case, if both dimensions of the drawing are
less than size, the drawing is scaled up uniformly until at
least one dimension equals its dimension in size.
Note that there is some interaction between the size and
ratio attributes.
- skew
- Skew factor for shape=polygon. Positive values
skew top of polygon to right; negative to left.
- splines
- If true, draw edges as splines. This requires non-overlapping
nodes (cf. overlap).
If fdp is used for layout, if splines="compound", then the edges are
drawn to avoid clusters as well as nodes.
- start
- Parameter used to determine the initial layout of nodes. By default,
nodes are randomly placed in a unit square.
The same seed is always used for the random number generator, so the
initial placement is repeatable.
- style
- Set style for node or edge. For cluster subgraph, if "filled", the
cluster box's background is filled.
- stylesheet
- A URL or pathname specifying an XML style sheet, used in SVG output.
- tailURL
- When the output format is imap or cmap, if tailURL is defined, it is
output as part of the tail label of the edge.
See limitation.
- tailclip
- If true, the tail of an edge is clipped to the boundary of the tail node;
otherwise, the end of the edge goes to the center of the node, or the
center of a port, if applicable.
- tailhref
- Synonym for tailURL.
- taillabel
- Text label to be placed near tail of edge.
See limitation.
- tailport
- Indicates where on the tail node to attach the tail of the edge.
See limitation.
- tailtarget
- If the edge has a tailURL,
this attribute determines 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 undefined, the value of the target is used.
- tailtooltip
- Tooltip annotation attached to the tail of an edge. This is used only
if the edge has a tailURL attribute.
- target
- If the object has a URL, this attribute determines which window
of the browser is used for the URL.
See W3C documentation.
- tooltip
- Tooltip annotation attached to the node or edge. This is used only
if the object has a URL attribute.
- truecolor
- If set explicitly to true or false, the value determines whether or not
internal bitmap rendering relies on a truecolor color model or uses
a color palette.
If the attribute is unset, truecolor is not used
unless there is a shapefile property
for some node in the graph.
The output model will use the input model when possible.
Use of color palettes results in less memory usage during creation of the
bitmaps and smaller output files.
Usually, the only time it is necessary to specify the truetype model
is if the graph uses more than 256 colors.
However, if one uses bgcolor=transparent with
a color palette, font
antialiasing can show up as a fuzzy white area around characters.
Using truecolor=true avoids this problem.
- vertices
- If the input graph defines this attribute, the node is polynomial,
and output is dot or xdot, this attribute provides the
coordinates of the vertices of the node's polynomial, in inches.
If the node is an ellipse or circle, the
samplepoints attribute affects
the output.
- viewport
- Clipping window on final drawing.
- voro_margin
- Factor to scale up drawing to allow margin for expansion in
Voronoi technique. dim' = (1+2*margin)*dim.
- weight
- Weight of edge. In dot, the heavier the weight, the shorter,
straighter and more vertical the edge is. In neato, the heavier the
weight, the more neato will try to place the end points so that the
length of the edge is len.
- width
- Width of node, in inches. This is taken as the initial, minimum width
of the node. If fixedsize is true, this
will be the final width of the node. Otherwise, if the node label
requires more width to fit, the node's width will be increased to
contain the label. Note also that, if the output format is dot, the
value given to width will be the final value.
- z
- Provides z coordinate value for 3D layouts and displays. If the
graph has dim set to 3 (or more),
neato will use a node's z value
for the z coordinate of its initial position if
its pos attribute is also defined.
Even if no z values are specified in the input, it is necessary to
declare a z attribute for nodes, e.g, using node[z=""]
in order to get z values on output.
Thus, setting dim=3 but not declaring z will
cause neato -Tvrml to
layout the graph in 3D but project the layout onto the xy-plane
for the rendering. If the z attribute is declared, the final rendering
will be in 3D.
- arrowType
| "normal" |  |
| "inv" |  |
| "dot" | 
| "invdot" |  |
| "odot" | 
| "invodot" |  |
| "none" | 
| "tee" |  |
| "empty" | 
| "invempty" |  |
| "diamond" | 
| "odiamond" |  |
| "ediamond" | 
| "crow" |  |
| "box" | 
| "obox" |  |
| "open" | 
| "halfopen" |  |
These are the basic arrow shapes. In addition, there is a grammar
of arrow shapes
which can be used to describe a collection of 1200 arrow shapes as
modifications of a primitive set of 9 arrows. The basic arrows shown
above contain all of the primitive shapes (e.g., normal,
box, tee, etc.)
plus ones that can be derived from the grammar (e.g., ediamond,
inv).
- clusterMode
- "local","global","none"
- color
| "#%2x%2x%2x" | RGB |
| "#%2x%2x%2x%2x" | RGBA |
| H[, ]+S[, ]+V | 0.0 <= H,S,V <= 1.0 |
| string | color name |
| "transparent" | No color |
Note that some output formats, e.g., mif,
only support a limited number of specific colors.
The color transparent is only available in the output formats
svg, dia, vmrl, and the bitmap formats. It can be used whenever a
color is needed but is most useful with
the bgcolor attribute.
- colorList
- A colon-separated list of color values: C(:C)*
where each C is a color value.
- dirType
- For an edge
T -> H;
| "forward" | 
| "back" |  |
| "both" | 
| "none" |  |
For undirected edges T -- H;, one of the nodes, usually
the righthand one, is treated as the head for the purpose of
interpreting "forward" and "back".
- escString
- string allowing escape sequences which are replaced according
to the context.
For node attributes, the substring "\N" is replaced by the name of the node,
and the substring "\G" by the name of the graph.
For graph or cluster attributes, the substring "\G" is replaced by the
name of the graph or cluster.
For edge attributes, the substring "\N" is replaced by the name of the edge,
and the substrings "\T" and "\H" by the names of the tail and head nodes,
respectively. The name of an edge is the string formed
from the name of the
tail node, the appropriate edge operator ("--" or "->") and the name of the
head node.
In addition, if the associated attribute is
label,
headlabel or taillabel,
the escape sequences "\n", "\l" and "\r"
divide the label into lines, centered, left-justified, and right-justified,
respectively.
- layerList
- list of strings separated by characters from the
layersep attribute (by default, colons,
tabs or spaces), defining layer
names and implicitly numbered 1,2,...
- layerRange
- layerId or layerIdslayerId,
where layerId = "all",
a decimal integer or a layer name.
(An integer i corresponds to layer i.)
The string s consists of 1 or more separator characters specified
by the layersep attribute.
- lblString
- an escString
or an HTML label.
- outputMode
- "breadthfirst","nodesfirst","edgesfirst"
These specify the order in which nodes and edges are drawn in concrete
output. The default "breadthfirst" is the simplest, but when the graph
layout does not avoid edge-node overlap, this mode will sometimes have
edges drawn over nodes and sometimes on top of nodes. If the mode
"nodesfirst" is chosen, all nodes are drawn first, followed by the
edges. This guarantees an edge-node overlap will not be mistaken for
an edge ending at a node. On the other hand, usually for aesthetic
reasons, it may be desirable that all edges appear beneath nodes, even
if the resulting drawing is ambiguous. This can be achieved by choosing
"edgesfirst".
- packMode
- "node","clust","graph"
These specify the granularity of packing connected components when
the pack attribute is true. A value of "node" causes
packing at the node and edge label, with no overlapping of these objects.
This produces a layout with the least area, but it also allows interleaving,
where a node of one component may lie between two nodes in another
component. A value of "graph" does a packing using the bounding box of the
component. Thus, there will be a rectangular region around a component
free of elements of any other component.
A value of "clust" guarantees that top-level clusters are kept intact.
What effect a value has also depends on the layout algorithm. For
example, neato does not support clusters, so a value of "clust" will
have the same effect as the default "node" value.
- pagedir
- "BL", "BR", "TL", "TR", "RB", "RT", "LB", "LT".
These specify the 8 row or column major orders for traversing a
rectangular array, the first character corresponding to the major
order and the second to the minor order. Thus, for "BL", the
major order is from bottom to top, and the minor order is from left
to right. This means the bottom row is traversed first, from left
to right, then the next row up, from left to right, and so on,
until the topmost row is traversed.
- point
- "%f,%f"('!') representing the point (x,y). The
optional '!' indicates the
node position should not change (input-only).
If dim is 3 or more, point may also have
the format "%f,%f,%f"('!') to represent the point (x,y,z).
- pointf
- "%lf,%lf" representing the point (x,y).
- pointfList
- list of pointf, separated by spaces.
- portPos
- modifier indicating where on a node an edge should be aimed.
It has the form portname[:compass_point]
or compass_point.
If the first form is used, the corresponding node must either have
record shape with one of its fields
having the given portname,
or have an HTML-like label, one of
whose components has a PORT attribute set to portname.
In this case, the edge is aimed for the center of the corresponding
field.
If a compass point is used, it must have the form
"n","ne","e","se","s","sw","w","nw". This modifies the edge
placement to aim for the corresponding compass point on the port or,
in the second form where no portname is supplied, on the node
itself.
This attribute can be attached to an edge using the
headport and
tailport attributes, or as part of the
edge description as in
node1:port1 -> node2:port5:nw;
- rankType
- "same", "min", "source", "max", "sink"
- rankdir
- "TB", "LR", "BT", "RL", corresponding to directed graphs drawn
from top to bottom, from left to right, from bottom to top, and from
right to left, respectively.
- rect
- "%d,%d,%d,%d" The rect llx,lly,urx,ury gives the coordinates, in
points, of the lower-left corner (llx,lly) and the upper-right corner
(urx,ury).
- shape
- A string specifying the shape of a node.
There are three
main types of shapes :
polygon-based,
record-based and
user-defined.
- splineType
- spline ( ';' spline )*
| where spline | = | (endp)? (startp)? point (triple)+ |
| and triple | = | point point point |
| and endp | = | "e,%d,%d" |
| and startp | = | "s,%d,%d" |
If a spline has points p1 p2 p3 ... pn, (n = 1 (mod 3)), the points
correspond to the control points of a B-spline from p1 to pn. If startp
is given, it touches one node of the edge, and the arrowhead
goes from p1 to startp. If startp is not given, p1 touches a node.
Similarly for pn and endp.
- startType
- has the syntax [style][seed].
If style is present, it must be one of the strings "regular",
"self", or "random". In the first case, the nodes are
placed regularly about a circle. In the second case,
an abbreviated version of neato is run to obtain the initial layout.
In the last case, the nodes are placed randomly in a unit square. This
is the default.
If seed is present, it specifies a seed for the random number
generator. If seed is a positive number, this is used as the
seed. If it is anything else,
the current time, and possible the process id, is used to pick a seed,
thereby making the choice more random. In this case, the seed value
is stored in the graph.
Note that input positions, specified by a node's
pos
attribute, are only used when the style is "random".
- style
- styleItem ( ',' styleItem )*
| where styleItem | = | name or name'('args')' |
| and args | = | name ( ',' name )* |
| and name | = | [^)(, ][^)(,]* |
Note that whitespace characters are ignored, except for names which
can containt them. A
name cannot any comma, or left or right parenthesis, and it cannot
begin with a whitespace character.
At present, the recognized style names comprise
"dashed", "dotted", "solid", "invis" and "bold" for nodes and edges,
and "filled", "diagonals" and "rounded" for nodes only.
Additional styles are available in
device-dependent form. Style lists are passed to device drivers, which
can use this to generate appropriate output.
At present, "rounded" cancels "filled", except for circles
and ellipses. This holds for the Mrecord shape, which is rounded by
definition.
- viewPort
- "%lf,%lf,%lf,%lf,%lf" The viewPort "W,H,Z,x,y"
specifies a viewport for the final image. The pair (W,H) gives the
dimensions (width and height) of the viewport image, in pixels.
Z is the zoom factor, i.e., 1 point corresponds to Z pixels.
For example, use Z=1.34 (= 96/72) with a screen resolution of 96dpi to
convert 1 inch (72 points) in the graph to 1 inch on the screen.
The pair (x,y) give the position in the graph, in points, of the center
of the viewport. To focus on a particular node, (x,y) can be set to the
pos attribute "x,y" of the node.
To center on the whole graph, use (bbx/2,bby/2), where "bbx,bby" is the
value of the bounding box attribute bb.