Exponential moving average with variable smoothing factor A channel with a non-smooth and stationary approximation error, in which the exponential moving average with a variable smoothing factor is used as the center line. This indicator is compiled not only as an MQL5 indicator, but also as a MQL4 indicator, for which you should change the extension of the indicator code to mq4, place the code in \ MQL4 \ Indicators and compile it with the appropriate code editor.