Chartists can also use the Price Relative to compare the performance of a stock to its sector or industry group. This makes it possible to determine if a stock is leading or lagging its peers . The Price Relative indicator can also be used to find stocks that are holding up better during a broad market decline or showing weakness during a broad market advance. (Source: stockcharts)
This also can be used for Trend Identification and / Divergences.
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.