how to display graphs using canvas element

While learning graph algorithms and canvas HTML element it stuck me that i should have a small g开发者_如何学运维raph library of my own in javascript which shows the graphs using canvas element can you point me in right direction so as i can read some code[js/python] as on how to display the graphs and write my own little lib.

PS : i mean edges and Node grapth not the bars and pie charts.

There are quite a few ways to display graphs using various layout algorithms. Two of the primary ones are a Force-Directed layout algorithm, which can be a continuous layout algorithm using a push-pull principle. Next is the GEM layout algorithm which uses a rudimentary physics approach to determine the best "fit".

Here are some examples:

http://vis.stanford.edu/protovis/ex/force.html

bitbucket.org/bwalenz/algorithms/src/

Protovis has probably the most functional. The bitbucket link is an implementation of the GEM algorithm but with no visualization. It just lays out the nodes/edges.

Not really using canvas, but quite a good JS solution for graphs: Raphael Charting plugin

The good thing about Raphael is that it works in all browsers, IE included.

Great lib, for graphics in canvas: processing.js: http://processingjs.org/ this is a graphic library, that allows you to write build amazing visualization using simple javascript code. have a look.