|
Otter
Description
Otter is a feature-rich 2D
graph visualization tool. It
includes a large number of features, such as the ability to attach
data to links or nodes. Most of Otter’s capabilities can be exploited using a
simple input file format, and the source code is purportedly very
easy to modify. Check
out this
use of Otter to display geographic AS data.
Layout
Otter
supports several automatic algorithms for laying out graphs.
The most useful algorithm picks a small number of roots and
arranges them in a circle.
Each nodes’ children are laid out in a semicircle
‘below’ it.
The radius of each semicircle depends on the parent
node’s number of children.
This layout algorithm produces nice output for graphs with
less than 100 nodes, but the output becomes messy as the graph
size increases.
Fortunately, Otter allows node positions to be explicitly
specified in the input file, so the graph can be preprocessed with
an external layout algorithm.
Interactivity
Otter supports all of the
standard interactive controls and more.
- Zoom,
pan, and center.
- Edit
node positions on the fly.
- Color
nodes and links by associated data values using a spectrum of
colors.
- Filter
nodes and links by associated data values.
- ‘Grow’
a graph breadth-first starting at the root.
- And
more...
Availability
Otter’s source and binary are freely available at CAIDA’s
website. Otter is
written in Java, and can be run as an applet from the same site.
Using
Otter
Otter is
exceptionally easy to use. The
input file format is a simple list of node and link definitions.
Data values can be bound into nodes and links.
Source code modifications are necessary only in the event
that additional features are required.
Links
CAIDA's
Otter
Page
|