change: 1-day % change
from ma: the % change from a moving average
corr idx: correlation of the contract to the GSCI
The lengths for the moving average and correlation statistic can be set using the inputs.
See the script source for the symbols used for each commodity. Although most of the symbols correspond to the actual futures contract used to compute the index, LME contracts are not available on tradingview. Hence, corresponding HKEX contracts are used for the industrial metals.
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.