"source" confusion

[IrvPrail]

I'm having a tough time determining the correct method of getting the new 7.9 indicators (primarily sma, ema, wma) to accept my locally-constructed variables as "source" -- sometimes this works beautifully, sometimes there's utter failure. I cannot find, by searching, any descrition of how to accomplish this. Shoulld I be using Arrays? Do I need to set my variables up as a "series"? Would you please provide (or point me to existing) examples? Thanks!!

[ACM]

IrvPrail
They need to be a series. You can find several examples in this thread showing how to build studies on studies using also custom variables and in this thread that explains the efsInternal() and efsExternal() functions
Alex