Ketzah
Indicator ROC
https://www.investopedia.com/terms/r/rateofchange.asp
https://mrjbq7.github.io/ta-lib/func_groups/momentum_indicators.html
ROC - Rate of change : ((price/prevPrice)-1)*100
Unsure of codebase for custom indicators, however
ROC = (((data.bar.close/data.last_bar.close)-1)*100)
or something along those lines