Veusz Tutorial. It was designed to be easy to use easily extensible but powerful. Veusz includes a built-in.
It can also be used as a module in Python for plotting. Please feel free to add useful information to the wiki. Veusz provides GUI Python module command line scripting DBUS and SAMP interfaces to its plotting facilities.
I have been using it extensively to create graphs on my website.
Button and click on the tutorial. Nothing can offer more accurate results than a computer application. It also includes manyexamples to show how certain kinds of plots are produced. The first video is here.
