python plot graph
http://puremonkey2010.blogspot.com/2012/02/network-x.html
https://networkx.github.io/documentation/networkx-2.1/_modules/networkx/generators/line.html
R Graphics
http://web.ntpu.edu.tw/~cflin/Teach/R/R06EN06Graphics.pdf
程式札記
http://puremonkey2010.blogspot.com/2015/10/python-python-zip.html
