Relative Derivative

//@version=5
indicator(title='Relative Derivative', shorttitle='RD')
src = input(close, title='source')
len = input.int(2, minval=1, title='length')
sm = input.int(12, minval=1, title='smooth')
rd(x, y) =>
    ta.sma((x - x[y]) / (x * y), sm)
plot(rd(src, len), color=color.new(color.yellow, 0))
hline(0, color=color.white)