Judging by the code of indicator, it calculates the difference between the maximum maximums and minimum minimums of prices of the candlesticks for the last 20 bars (parameter).
The result is displayed in points.
extern int N=20; // period of the channel
This set of functions enables one to capture mouse events on your trading chart. One can simmulate buttons to trigger actions in the EA.Extrapolator
Extrapolator is a result of my long-term research in the area of the Timeseries Forecasting.