Theory : In the original RSI calculation Welles Wilder is using the "Wilder EMA" (some explanation of it can be found here : Double Smoothed Wilder's EMA). He never explained exactly why he was that EMA but we can guess that he was trying to reduce the number of signals f...
from https://tradingrobots.net/rsi-with-double-smoothed-wilders-ema-indicator-for-metatrader-5/