Optmized Chuyuan's algorithm and create examples for IPython Notebook.
Merge pull request #3 from shaohu/master

Optmized Chuyuan's algorithm and create examples for IPython Notebook.
update the mtehod of rectangle_init and examples in ipython notebook examples
Merge pull request #4 from shaohu/master

update the method of rectangle_init and examples in ipython notebook exa...