强大的JS画图工具 – JSXGraph
有N多示例，相信有你想要的.
JSXGraph is a cross-browser library for interactive geometry, function plotting, graphs, and data visualization in a web browser. It is implemented completely in JavaScript and uses SVG and VML.
JSXGraph is easy to embed and has a small footprint: only about 55 KB if embedded in a web page. No plug-ins are required! JSXGraph uses the JavaScript libraries/frameworks Prototype or jQuery.
JSXGraph is developed at the Lehrstuhl für Mathematik und ihre Didaktik, University of Bayreuth, Germany.
