Chaco

A Brief History, Progress Update, and Future Directions

Peter Wang

Enthought, Inc.

What is Chaco?

Chaco is a plotting application toolkit for Python. You use it to build stand-alone plotting applications, or embed it inside any application that needs to visualize numerical data.

Sample plotting applications:

• batch plotting of data
• interactive data inspector
• realtime data acquisition and plotting
• plot/graph constructor

More plotting applications

It's not all scientific-y stuff!

• sound waveform editor
• graphic equalizer
• graphical stock ticker
• Google Maps

Any time you want to view numerical information in a structured way, you are doing plotting.

What makes Chaco special?

• Chaco has an architecture that facilitates viewing interrelated data
• Chaco is designed from the ground up to be interactive (user interaction and data inspection)

That's enough!

• many, many plotting apps out there
• not many that are real "toolkits" (jfreechart, INT widgets)
• fewer are designed for really interactive use
• even fewer are free
• none (that I'm aware of) in Python

Most of the hard math problems are solved or patented: contouring, label placement, fast 2d graphics routines.

What remains is the software challenge. A good toolkit provides modular pieces that play well together. They must map onto the problem domain (plotting) in a coherent way.

A brief history

• Originally developed a few years ago by Dave Morrill and others
• Remained relatively dormant for a couple of years
• Now undergoing re-architecting and rewrite: Chaco

Architecture

• Data objects: DataSource, DataRange, Mapper
• Plotting side: Mapper, Renderer, Axis, Grid
• Containers & Frames

Demos

The Near and Far Future

• Port renderers from old Chaco
• polar
• command-line plotting (matlab-style interface)
• 3D
• 4D!

How to get it

http://code.enthought.com/chaco

Mailing lists: scipy-chaco@scipy.org, enthought-dev@enthought.com

Get Enthon! http://code.enthought.com/enthon