Pine Script - Fisher Transform with Up Down

study("Fisher and Cross")
// Fisher Transform and Crosses, Rev 01
// Junk Still - Working Copy
// https://getsatisfaction.com/tradingview/topics/seeking_script_writer_to_enhance_a_current_indicator
//
// Rewrite for Tradingview "Pine Script" by Kocurekc, April 2014
// https://getsatisfaction.com/tradingview/
// https://www.tradingview.com/u/kocurekc/
// Code is provided as public domain, no warranty

LB = input(title="Lookback Period", type=integer, defval=31, minval=2)
//SO = input(title="Signal Offset Factor", type=float, defval=0.20, minval=0.01)
IT = input(title="Input Threshold", type=float, defval=1.50, minval=0.01)

Value1 = (0.33*2)*((hl2 - lowest(low, LB))/(highest(high, LB) - lowest(low, LB)) - 0.5) + 0.6667*(nz(Value1[1]))
Value2 = Value1 > 0.99 ? 0.999 : Value1 < -0.99 ? -0.999 : Value1
Fisher = 0.5 * log((1+Value2)/(1-Value2)) + 0.5 * nz(Fisher[1])
Trigger = nz(Fisher[1])

plot(Fisher, style=histogram, color=red)
plot(Trigger, color=black)

trendDown = Fisher < Fisher[1] ? Fisher[1] > Fisher[2] ? Fisher[1] >= IT ? -1 : 0 : 0 : 0
trendUp = Fisher > Fisher[1] ? Fisher[1] < Fisher[2] ? Fisher[1] <= -IT ? 1 : 0 : 0 : 0

plot(trendUp, style=columns, color=green)
plot(trendDown, style=columns, color=red)