unshifty

jmapower    = input(title="JMA Power", type=input.integer, defval=2)
jmaphase    = input(title="Phase", type=input.integer, defval=50)
jma(src, length, phase, power) =>
    phaseRatio = phase < -100 ? 0.5 : phase > 100 ? 2.5 : phase / 100 + 1.5
    beta = 0.45 * (length - 1) / (0.45 * (length - 1) + 2)
    alpha = pow(beta, power)
    jma = 0.0
    e0 = 0.0
    e0 := (1 - alpha) * src + alpha * nz(e0[1])
    e1 = 0.0