[AS] RSI

study(title="[AS] RSI", shorttitle="[AS] RSI", overlay=true)
src = close, len = input(14, minval=1, title="Length")
up = rma(max(change(src), 0), len)
down = rma(-min(change(src), 0), len)
rsi = down == 0 ? 100 : up == 0 ? 0 : 100 - (100 / (1 + up / down))

isCall() => rsi > 30 and rsi[1] < 30
isPut() => rsi < 70 and rsi[1] > 70

b_color = (isPut() ? red : isCall() ? green : na)
bgcolor(b_color)