function TrendStrengthESeries( Series: Integer; PeriodStart: Integer ; PeriodEnd: Integer ; Step: integer): integer;)
begin
  var Bar: integer;
  var sName: string;
  var Value: float;
  var i, dummy:integer;
  var SMAval, maxval:float;
  var lst: TList;
  sName := 'TrendStrengthE(' + GetDescription( Series ) + ',' + IntToStr( PeriodStart ) + ',' + IntToStr( PeriodEnd )+ ','+Inttostr(step)+')';
  Result := FindNamedSeries( sName );
  if Result >= 0 then
    Exit;
  Result := CreateNamedSeries( sName );
  If PeriodStart>PeriodEnd then
    begin //make sure start<end
    dummy:=PeriodStart;
    PeriodStart:=PeriodEnd;
    PeriodEnd:=dummy;
    end;
  SingleCalcMode(true); //to increase speed
  lst := TList.Create; // Create list object
  for Bar := PeriodEnd to BarCount() - 1 do
    begin
    lst.Clear;
    i:=PeriodStart;
    Repeat //loop through all SMA periods
      begin
      SMAVal := SMA(Bar, Series, i);
      lst.AddData( SMAval, (i-periodstart)/step ); //store SMA value and order of SMA (starting with 0)
      i:=i + step; //increase by step
      end;
    Until i>PeriodEnd;
    lst.SortNumeric;
    Value:=0;
    for i:=0 to int(lst.count-1) do //sum up all square-differences
       value := value + sqr(i-lst.data(i));
    maxval := 0; //calc maximum value of the indicator (to normalize it)
    for i:=int(lst.count/2-1) downto 0 do
        maxval:= maxval + sqr(lst.count - 1 - 2*i);
    SetSeriesValue( Bar, Result, Value / Maxval - 1 );
    end;
  SingleCalcMode(false); //Restore settings to normal values
end;

function TrendStrengthE( Bar: integer; Series: Integer; PeriodStart: Integer; PeriodEnd: Integer ; Step: integer): float;
begin
  Result := GetSeriesValue( Bar, TrendStrengthESeries( Series, PeriodStart, PeriodEnd, Step ) );
end;