The real author:
Guru
The Moving Average that represents itself a linear combination of the EMA smoothing series by the Exponential Moving Average (EMA).
The indicator uses SmoothAlgorithms.mqh library classes (must be copied to the terminal_data_folder\MQL5\Include). The use of the classes was thoroughly described in the article “Averaging price series for intermediate calculations without using additional buffers”.
This indicator was first implemented in MQL4 and published in Code Base on 16.09.2008.
Fig.1 The DecEMA indicator