Williams Fractals [Tutorial/Template]

I noticed there weren't any code templates for Williams Fractals, therefore I have written this script to be a template and tutorial for those learning Pine Script. Each line is commented to show what it does.

If you don't know what Williams Fractals are, here is a brief explanation.

Bill Williams Fractals is a lagging indicator used to plot trend reversals on a chart. These appear over a candle at the point of reversal 2 candles after it has occurred. Often times this indicator is used in strategies such as Mumbai Scalping and paired with trend direction indicators and trailing stop indicators such as Parabolic SAR and SuperTrend.
Skript med en öppen källkod

In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.

Vill du använda det här skriptet i ett diagram?
// Bill Williams Fractal Template
// Coded By: Matthew Spencer
// If you like this script or use it's code in one of yours, please donate.
// PayPal: ma.spencer@gmx.com Bitcoin: 1foxypuyuoNp5n1LNCCCCmjZ4RAXntQ8X

// Define our title and that this script will overlay the candles.
study("Williams Fractals",shorttitle="Fractals", overlay=true)

// Define "n" as the number of periods and keep a minimum value of 2 for error handling.
n = input(title="Periods", defval=2, minval=2, type=integer)

// Williams Fractals are a 5 point lagging indicator that will draw 2 candles behind.
// The purpose of the indicator is to plot points of trend reversals.
// Often these are paired with trailing stop indicators such as Parabolic SAR, Volatility Stop, and SuperTrend.

// Down pointing fractals occur over candles when:
//   High(n-2) < High(n)
//   High(n-1) < High(n)
//   High(n + 1) < High(n)
//   High(n + 2) < High(n)
dnFractal = (high[n-2] < high[n]) and (high[n-1] < high[n]) and (high[n+1] < high[n]) and (high[n+2] < high[n])

// Up pointing fractals occur under candles when:
//   Low(n-2) > Low(n) 
//   Low(n-1) > Low(n)
//   Low(n + 1) > Low(n) 
//   Low(n + 2) > Low(n)
upFractal = (low[n-2] > low[n]) and (low[n-1] > low[n]) and (low[n+1] > low[n]) and (low[n+2] > low[n])

// Plot the fractals as shapes on the chart.
plotshape(dnFractal, style=shape.arrowdown, location=location.abovebar, offset=-2, color=olive, transp=0) // Down Arrow above candles
plotshape(upFractal, style=shape.arrowup, location=location.belowbar, offset=-2, color=maroon, transp=0)  // Up Arrow below candles