Gnuplot is by far my favorite way to generate plots. Here's a simple template you can modify to make similar figures.

You can download the script here on hackaday.io . It comes with the sample data file required for the plot above. Invoke the script like this:

gnuplot plot_example.gpt

You can find lots of examples and documentation for gnuplot on the web; this example is mainly useful to get the colors right.