Wilder_RSI

//@version=5
library(title = "Wilder_RSI", overlay = false)
export Wilder_RSI(float source, int length) =>
    delta = source - source[1]
    plus = math.sum(delta > 0 ? delta : 0, length)
    minus = math.sum(delta < 0 ? delta : 0, length)
    plus / (plus- minus) * 100
plot(Wilder_RSI(source = close, length = 12))