环境：ubuntu 15.04
edemon@edemon-virtual-machine:~$ sudo apt-get install gnuplot gnuplot-x11
[sudo] password for edemon:
正在读取软件包列表... 完成
正在分析软件包的依赖关系树
正在读取状态信息... 完成
将会安装下列额外的软件包：
aglfn gnuplot-data gnuplot-tex liblua5.1-0
……
edemon@edemon-virtual-machine:~$ gnuplot
G N U P L O T
Version 4.6 patchlevel 6 last modified September 2014
Build System: Linux i686
Copyright (C) 1986-1993, 1998, 2016, 2007-2016
Thomas Williams, Colin Kelley and many others
gnuplot home: http://www.gnuplot.info
faq, bugs, etc: type "help FAQ"
immediate help: type "help" (plot window: hit 'h')
绘制二维图像：
gnuplot> plot sin(x)
绘制三维图像：
gnuplot> splot sin(x*y/30)
gnuplot> splot(y/x)
退出：gnuplot> quit