123 Reversal and Fisher Transform Indicator Combo Strategy

/*backtest
start: 2023-08-13 00:00:00
end: 2023-09-12 00:00:00
period: 4h
basePeriod: 15m
exchanges: [{"eid":"Futures_Binance","currency":"BTC_USDT"}]
*/

//@version=4
////////////////////////////////////////////////////////////
//  Copyright by HPotter v1.0 28/08/2020
// This is combo strategies for get a cumulative signal. 
//
// First strategy
// This System was created from the Book "How I Tripled My Money In The 
// Futures Market" by Ulf Jensen, Page 183. This is reverse type of strategies.
// The strategy buys at market, if close price is higher than the previous close 
// during 2 days and the meaning of 9-days Stochastic Slow Oscillator is lower than 50. 
// The strategy sells at market, if close price is lower than the previous close price 
// during 2 days and the meaning of 9-days Stochastic Fast Oscillator is higher than 50.
//
// Second strategy
// 	Market prices do not have a Gaussian probability density function
// 	as many traders think. Their probability curve is not bell-shaped.
// 	But trader can create a nearly Gaussian PDF for prices by normalizing
// 	them or creating a normalized indicator such as the relative strength
// 	index and applying the Fisher transform. Such a transformed output 
// 	creates the peak swings as relatively rare events.
// 	Fisher transform formula is: y = 0.5 * ln ((1+x)/(1-x))
// 	The sharp turning points of these peak swings clearly and unambiguously
// 	identify price reversals in a timely manner. 
//
// WARNING:
// - For purpose educate only
// - This script to change bars colors.
////////////////////////////////////////////////////////////
Reversal123(Length, KSmoothing, DLength, Level) =>
    vFast = sma(stoch(close, high, low, Length), KSmoothing) 
    vSlow = sma(vFast, DLength)
    pos = 0.0
    pos := iff(close[2] < close[1] and close > close[1] and vFast < vSlow and vFast > Level, 1,
	         iff(close[2] > close[1] and close < close[1] and vFast > vSlow and vFast < Level, -1, nz(pos[1], 0))) 
	pos


FTI(Length) =>
    pos = 0
    nValue1 =0.0
    nFish = 0.0
    xHL2 = hl2
    xMaxH = highest(xHL2, Length)
    xMinL = lowest(xHL2,Length)
    nValue1 := 0.33 * 2 * ((xHL2 - xMinL) / (xMaxH - xMinL) - 0.5) + 0.67 * nz(nValue1[1])
    nValue2 = iff(nValue1 > .99,  .999,
	             iff(nValue1 < -.99, -.999, nValue1))
    nFish := 0.5 * log((1 + nValue2) / (1 - nValue2)) + 0.5 * nz(nFish[1])
    pos := iff(nFish > nz(nFish[1]), 1,
     	     iff(nFish < nz(nFish[1]), -1, nz(pos[1], 0)))  
    pos

strategy(title="Combo Backtest 123 Reversal & Fisher Transform Indicator", shorttitle="Combo", overlay = true)
Length = input(15, minval=1)
KSmoothing = input(1, minval=1)
DLength = input(3, minval=1)
Level = input(50, minval=1)
//-------------------------
LengthFTI = input(10, minval=1)
reverse = input(false, title="Trade reverse")
posReversal123 = Reversal123(Length, KSmoothing, DLength, Level)
posFTI = FTI(LengthFTI)
pos = iff(posReversal123 == 1 and posFTI == 1 , 1,
	   iff(posReversal123 == -1 and posFTI == -1, -1, 0)) 
possig = iff(reverse and pos == 1, -1,
          iff(reverse and pos == -1 , 1, pos))	   
if (possig == 1) 
    strategy.entry("Long", strategy.long)
if (possig == -1)
    strategy.entry("Short", strategy.short)	 
if (possig == 0) 
    strategy.close_all()
barcolor(possig == -1 ? #b50404: possig == 1 ? #079605 : #0536b3 )