High Frequency Historical Volatility

//@version=4
study("High Frequency Historical Volatility (2)",precision=2)
bgcolor(#000000c0)
Annual = input(365,title = "Trading Days in one Year")
Month = input(30,title = "Trading Days in one Month")
// Security
reso = input(defval="5", title="Historical Volatility Sampling Resolution")

//High Frequency Historical Volatility
m = input(288, minval=1,title="Number of sampling returns per bar") //Default = 24*60(minutes in one bar(1 day))/5 (sampling resolution) = 288
k = Annual*m
n = Month*(m+1)
//n = (Month-1)*(m+1)
change = log(close / nz(close[1]))
variance = sum(pow(change, 2), m)
v = security(syminfo.tickerid, reso, variance)
c2 = log(open/nz(close[1])) //Gap


Hv = sqrt((k/n) * (sum(v+pow(c2,2),Month)))*100


//Historical Volatility Percentile coloring
malen = input (30, "Ma Length")
sma = input(false, "Plot Moving Average")
Columns = input(false,"Style Columns")
ma= sma(Hv, malen)
Hvp = percentrank(Hv,  Annual)

Color= Hvp >= 95 ? color.new(color.red,0): Hvp >= 80 ? color.new(color.orange,0) : Hvp >= 70 ? color.new(color.yellow,0) : Hvp >= 30 ? color.new(color.blue,0) : Hvp >= 10 ? color.new(color.aqua,0) : Hvp >= 5 ?color.new(color.silver,0) : color.new(color.white,0)




plot(Hv, color=Color,transp=0,linewidth=3,style= Columns?plot.style_columns : plot.style_line)
plot(sma?ma:na, color=color.lime, transp=0, linewidth=2)
hline(0)