I know that for some indicators there exists an `...OnArray()` version in MQL4 (e.g.: `iMAOnArray()`, `iRSIOnArray()` etc.). But what if I have a custom indicator and I want to calculate that indicator on an array from a custom dataset? It seems iCustom() doesn't support this. I'd be surprised if indicator calculation on an array of values was only possible for a few indicators and this feature wouldn't be generalizable.