Recursive Moving Trendline Indicator

Type : Indicator, Name : Recursive Moving Trendline Indicator

inputs: ndays(25); vars: alpha(0),
bo(0),
bo1(c),
xest(0),
xest1(c),
ema(0),
ema1(c);

alpha = 2 / (ndays + 1);

bo = (1 - alpha) * bo1 + close;
ema = ema1 + alpha * (close - ema1);
xest = (1 - alpha) * xest1 + alpha * (close + bo - bo1);

bo1 = bo;
xest1 = xest;
ema1 = ema;

if barnumber > 50 then begin
plot1(xest,"Xest");
plot2(ema,"EMA");
end;