NEATO(1) (12 August 1994) NEATO(1)
NAME
neato - preprocessor for drawing undirected graphs
SYNOPSIS
neato [-Gname=value] [-Nname=value] [-Ename=value] [-Tlang]
[-l libfile] [-o outfile] [-v] [files]
DESCRIPTION
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. To make
Postscript, use the -Tps option. FrameMaker MIF (-Tmif),
HPGL (-Thpgl), and GIF (-Tgif) are other choices.
Here is a brief synopsis of the graph language.
graph name { statement-list } is the top level graph.
Statements may be:
name=val;
node [name=val];
edge [name=val]; Set the default graph, node, or edge
attribute name to val. Any subgraph, node, or edge speci-
fied after one of these statements inherits these
attributes.
n0 [name0=val0,name1=val1,...]; Creates node n0 if it does
not 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 optionally sets the
given attributes. Creates nodes as necessary.
subgraph name { statement-list } Creates a subgraph. A sub-
graph may appear in place of an individual node within an
edge statement. The subgraph name part is optional. If
missing, the subgraph is given an internal name.
While attribute names and values may be arbitrary strings,
certain fixed attributes control neato's layout algorithm,
as next described.
GRAPH ATTRIBUTES
Refer to dot(1) options to control the layout size. In
addition, neato recognizes the following:
start=val. Requests random initial placement and seeds the
NEATO(1) (12 August 1994) NEATO(1)
random number generator. If val is not an integer, the pro-
cess ID or current time is used as the seed.
epsilon=n. Sets the cutoff for the solver. The default is
0.1.
NODE ATTRIBUTES
Refer to dot(1) for options to control node labels, shapes,
sizes, colors, fonts, etc.
EDGE ATTRIBUTES
Refer to dot(1) for options to control edge line style and
labels. In addition neato recognizes the following:
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.
COMMAND LINE OPTIONS
-v (verbose) prints delta energy every 100th iteration.
EXAMPLE
graph test123 {
a -- b -- c;
a -- {x y};
x -- c [w=10.0];
x -- y [w=5.0,len=3];
}
CAVEATS
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.
SEE ALSO
dot(1)
S. C. North, "NEATO User's Manual". Available on
research.att.com in dist/drawdag/neatodoc.ps.Z.