Fisher Transform Strategy

study(title="Fisher Transform (LastBattle)", shorttitle="Fisher (LastBattle)")

/// Define graph data
src = close
src_high = high
src_low = low

/// User input length
fisherlen = input(21, minval=1, title="Fisher Length")

// Fisher
Price = (src_high + src_low) / 2
MaxH = highest(src_high, fisherlen) 
MinL = lowest(src_low, fisherlen)

Value1 = max(-0.9999, min(0.9999, 0.5 * 2 * ((Price - MinL) / (MaxH - MinL) - 0.5) + 0.5 *  nz(Value1[1])))

Fish = 0.25 * log((1 + Value1) / (1 - Value1)) + 0.5 * nz(Fish[1]) 

/// Plot
plot(Value1, color=green)
plot(nz(Fish[1]), color=red) // trigger/signal line

// Background color
//sellSignal = (nz(Fish[1]) < -0.3 and nz(Fish[1]) > 0.9 * nz(Fish[1]))
//bgcolor(sellSignal ? red : white, transp=90)

// Band range
band_green_top = hline(.6999)
band_green_bottom = hline(.9999)
fill(band_green_top, band_green_bottom, color=green, transp=90)

band_red_top = hline(-.6999)
band_red_bottom = hline(-.9999)
fill(band_red_top, band_red_bottom, color=red, transp=90)