I am trying to smooth a 13 period EMA Elder Force Index in c++, and nobody really describes this as anything more than : Force Index(1) = {Close (current period) - Close (prior period)} x Volume. Force Index(13) = 13-period EMA of Force Index(1). I must be a bit thick, but when you use a moving average with a period, you get an average of that period, and then use that as a reference for further day MA's. I have calculated SMA & Exp MA for exstensive data sets before, but how are you supposed