And some Tweaks.
Linear Regression = n period LR forecast
Flat = Same Candle (If price don't move)
Forecast Code Source = yatrader2
In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.