Instruments Correlation [TradingView Custom Indicator]

//
// @author LazyBear
// If you use this code in its original / modified form, do drop me a note. Thx.
//
study(title = "Instruments Correlation [LazyBear]", shorttitle="CC_LB")
ccSymbol=input("DOWI", title="Correlation Symbol", type=symbol)
lengthCorrelation=input(20)
lengthMA=input(10)
s2=close
s1=security(ccSymbol, period, close)
c=correlation(s1, s2, lengthCorrelation)

plot(c, color=red, style=area)
plot(sma(c, lengthMA), color=navy, linewidth=2)
hline(0, color=gray)
u=hline(0.2, color=maroon)
l=hline(-0.2, color=maroon)
fill(u,l, maroon)
hline(1.0, color=green, linewidth=2,  title="Perfect positive correlation")
hline(-1.0, color=red, linewidth=2,  title="Perfect negative correlation")