Ergotic TSI Strategy

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//  Copyright by HPotter v1.0 17/07/2014
// r - Length of first EMA smoothing of 1 day momentum        4
// s - Length of second EMA smoothing of 1 day smoothing      8    
// u- Length of third EMA smoothing of 1 day momentum         6  
// Length of EMA signal line                                  3
// Source of Ergotic TSI                                      Close
//
// This is one of the techniques described by William Blau in his book "Momentum,
// Direction and Divergence" (1995). If you like to learn more, we advise you to 
// read this book. His book focuses on three key aspects of trading: momentum, 
// direction and divergence. Blau, who was an electrical engineer before becoming 
// a trader, thoroughly examines the relationship between price and momentum in 
// step-by-step examples. From this grounding, he then looks at the deficiencies 
// in other oscillators and introduces some innovative techniques, including a 
// fresh twist on Stochastics. On directional issues, he analyzes the intricacies 
// of ADX and offers a unique approach to help define trending and non-trending periods. 
// You can use in the xPrice any series: Open, High, Low, Close, HL2, HLC3, OHLC4 and ect...
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study(title="Ergotic TSI Strategy")
r = input(4, minval=1)
s = input(8, minval=1)
u = input(6, minval=1)
SmthLen = input(3, minval=1)
hline(0, color=blue, linestyle=line)
xPrice = close
xPrice1 = xPrice - xPrice[1]
xPrice2 = abs(xPrice - xPrice[1])
xSMA_R = ema(ema(ema(xPrice1,r), s),u)
xSMA_aR = ema(ema(ema(xPrice2, r), s),u)
Val1 = 100 * xSMA_R
Val2 = xSMA_aR
xTSI = iff (Val2 != 0, Val1 / Val2, 0)
xEMA_TSI = ema(xTSI, SmthLen)
pos =	iff(xTSI > xEMA_TSI, 1,
	    iff(xTSI < xEMA_TSI, -1, nz(pos[1], 0))) 
barcolor(pos == -1 ? red: pos == 1 ? green : blue )
plot(xTSI, color=green, title="Ergotic TSI")
plot(xEMA_TSI, color=red, title="SigLin")