This W3C-<i>invalid</i> plot was created with <a href="https://en.wikipedia.org/wiki/Gnuplot" class="extiw" title="w:Gnuplot">Gnuplot</a>.
<a href="//commons.wikimedia.org/wiki/User:Alejo2083" title="User:Alejo2083">Alessio Damato</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>