From Investopedia "The Price Rate of Change (ROC) is a momentum-based technical indicator that measures the percentage change in price between the current price and the price a certain number of periods ago.
The ROC indicator is plotted against zero, with the indicator moving upwards into positive territory if price changes are to the upside, and moving into negative territory if price changes are to the downside."
In this script, ROC length (the moment from when ROC is calculated) is set by detected trend change. Trend change is marked by indicators background colour.
"Trend Lenght" - Adjust this to fit the security and time frame