Illustration of partial reflection of a wave.  A gaussian wave on a one-dimensional string strikes a boundary with <a href="https://en.wikipedia.org/wiki/transmission_coefficient_(optics)" class="extiw" title="w:transmission coefficient (optics)">transmission coefficient</a> of 0.5.  Half the wave is transmitted and half is reflected.
<a href="//commons.wikimedia.org/wiki/User:Oleg_Alexandrov" title="User:Oleg Alexandrov">Oleg Alexandrov</a>
2007-11-26
self-made with MATLAB, source code below