# compute technical indicators from candle data

i have a rookie question but can't find the answer anywhere so..what is the right way to compute a simple moving average when you have an array of (open,close,low,high) tuples ? From what i saw so far it is the closing price that must be taken but i'm clearly not sure, i guess it could as well be open, or (open + close)/2, or anything else..Also, can this be generalized to other indicators ?

thank you very much.