JG, like Jako MACD not my thing (like most indicators had a play...

JG, like Jako MACD not my thing (like most indicators had a play over the years but long since discarded as I prefer to just "look" at price action ... sometimes with an MA (or 2 ) attached and about only indicator I look at is RSI now)

... but back to your q; not sure what prob you r having as (from memory, I might have some of this wrong?);

- the MACD is just a subtraction of 2 numbers (2 different MA's)
- the trigger line is just an MA of the MACD
- an MA is just an average of a sequence of numbers and
- an EMA is just a "fancy MA" which gives a weighting to more recent numbers

I am not sure how a zero in the equation is an issue.

Doubt any of that helped??? but lastly I am sure u have looked here; http://en.wikipedia.org/wiki/Moving_average
Good luck g