Trend Trader

////////////////////////////////////////////////////////////
//  Copyright by HPotter v1.0 21/08/2014
// This is plots the indicator developed by Andrew Abraham 
// in the Trading the Trend article of TASC September 1998  
////////////////////////////////////////////////////////////
study(title="Trend Trader", overlay = true)
Length = input(21, minval=1),
Multiplier = input(3, minval=1)
avgTR      = wma(atr(1), Length)
highestC   = highest(Length)
lowestC    = lowest(Length)
hiLimit = highestC[1]-(avgTR[1] * Multiplier)
loLimit = lowestC[1]+(avgTR[1] * Multiplier)
ret = iff(close > hiLimit and close > loLimit, hiLimit,
        iff(close < loLimit and close < hiLimit, loLimit, nz(ret[1], 0)))
plot(ret, color= blue , title="Trend Trader")