MCD

declare lower;

input price = hl2;
input length = 5;
input averageLength = 2;
input over_bought = 80;
input over_sold = -80;

assert(length >= 2, "'length' must be greater than or equal to 2: " + length);

def sumSqr = fold i = 0 to length with sum do
sum + Sqr((length - i) - fold j = 0 to length with rank
do rank + if GetValue(price, i, length - 1) > GetValue(price, length - j - 1) or GetValue(price, i) == GetValue(price, length - j - 1) and i <= length - j - 1 then 1 else 0);

plot Spearman = 100 * (1 - 6 * sumSqr / (length * (Sqr(length) - 1)));
plot SpearmanAverage = Average(Spearman, averageLength);
plot OverBought = over_bought;
plot ZeroLine = 0;
plot OverSold = over_sold;

Spearman.SetDefaultColor(GetColor(9));
SpearmanAverage.SetDefaultColor(GetColor(8));
OverBought.SetDefaultColor(GetColor(5));
ZeroLine.SetDefaultColor(GetColor(5));
OverSold.SetDefaultColor(GetColor(5));