A very useful function devised by Julius von Hann, and frequently confused with a similar function, devised by Richard W. Hamming.  Thus the name <i>Hanning</i> is a misnomer, but a surprisingly popular one!
<a href="https://de.wikipedia.org/wiki/Benutzer:Studi111" class="extiw" title="de:Benutzer:Studi111">Benutzer:Studi111</a>
5 January 2007 (original upload date)
This  diagram was created with <a href="https://en.wikipedia.org/wiki/Mathematica" class="extiw" title="w:Mathematica">Mathematica</a>.