Historical Volatility

var i,period: integer;
begin
  if ESPL=51 then begin
    SetUser(ePosition,eChart); {plot on the chart}
    SetUser(ePercent,true);    {percent scale}
    SetUser(ePlot1,True);      {plot 1st array}
    SetUser(eShow1,True);      {show 1st array}
    period:=GetUser(eParm1);   {read 1st parameter}
    for i:=BarLeft to BarEnd do SetUser(1,Volatility(i,period),i);
  end;
end;

Display a chart, and add user study #51 by clicking on the #1 button on the study drop down panel.   On the parameter form for the study, enter 20 as the 1st parameter for the number of periods.   The study will overlay the bar chart as a percent ranging from 0 to 100.   Typical historical volatility values plot in the 10 to 30 range.

All of the hard work is done by the new math function called Volatility.   You can read about this function in the ESPL help documentation.