The RS . is similar to the formulation of RS by IBD before rank among all the stocks in the market.
The lookback period is relaxed for customizing. Once you set the total lookback period, representing the 4Q, in the indicator, the other shorter lookback periods will be auto-calculated, namely, 1Q, 2Q, 3Q.
A of the RS . is also added for your easier analysis on the trend development of the strength.
To use it later at your charting later,
1. Favorite it;
2. Select from your favorite list.
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.