Logistics Sigmoid Oscillator

//@version=5
indicator(title="Logistics Sigmoid Oscillator", shorttitle="LOSC", overlay=false, timeframe="", timeframe_gaps=true)
len_main = input.int(36, minval=1, title="Length")

// CALCULATIONS
main_line = ta.ema(hl2, len_main)
price_line = ta.ema(hl2, 3)
stdev_main = ta.stdev(hl2, len_main)

z_score = (price_line - main_line) / stdev_main
sigmoid = 2 * (math.pow(1 + math.exp(-z_score), -1) - 0.5)

// COLORS
black_transp = color.new(color.black, 100)
red = color.new(color.red, 60)
green = color.new(color.green, 60)

// LINES
l_100_up = hline(1, linestyle=hline.style_solid, editable=false)
l_50_up = hline(0.5, linestyle=hline.style_dotted, editable=false)
l_00 = hline(0, color=black_transp, editable=false)
l_50_dw = hline(-0.5, linestyle=hline.style_dotted, editable=false)
l_100_dw = hline(-1, linestyle=hline.style_solid, editable=false)

// PLOT
fill(l_100_up, l_00, 1, 0, red, black_transp, editable=false)
fill(l_100_dw, l_00, 0, -1, black_transp, green, editable=false)

plot(sigmoid, title="Sigmoid", color=color.blue, style=plot.style_line, editable=false)
plot(ta.ema(sigmoid, 3), title="Smoothing", color=color.red, style=plot.style_line, editable=false)