http://web.archive.org/web/20070720222047/http://www.mesasoftware.com/Papers/What%27s+the+Difference.exe (self-extracting zip file)
The median-average adaptive filter by John Elhers is an EMA (see Exponential Moving Average) with an alpha smoothing factor that varies according to how close it is to a median.
The raw alpha values can be viewed as “Median-Average Alpha” in the lower indicator window, under “Low Priority” in the indicator lists. High values are where the average is following recent prices closely. The maximum is 0.5, which corresponds to a 3-day EMA.
Copyright 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2014, 2015, 2016, 2017 Kevin Ryde
Chart is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.