Hey Derek,
I have Alpari’s demo (MT4) installed (I didn’t realise this was the broker who you were trading with). I checked their ‘standard’ ADX with my ADX at both Delta and GCI. Alpari and GCI are ‘closer’ to each other I’ll admit (but there is a big timing difference between them so they will be slightly different). What I find interesting when comparing Delta’s to the others is that the ADX peaks appear to occur at roughly the same time BUT are far less pronounced and I have a very sneaky suspicion that it’s because Delta does INDEED ‘smooth’ the moving averages and the others do not (GCI I’m SURE does NOT make use of ‘smoothing’ as per Wilder i.e. the function is just not available).
Just one other thing though (that I believe is worth mentioning): while I do agree with you wholeheartedly that it’s imperative to have the correct calculations and agree the results with the results in ‘the book’ there are many variables that may affect the end result of the calculations (we’ve mentioned three already i.e. the different timezones, whether or not the moving averages are ‘smoothed’ as per ‘the old man’ or not, and the different price quotes). Off hand I can even think of one more i.e. SOME brokers show the ‘gaps’ (like Delta) and other do not (like GCI). ALL of this can make a difference to the end result of your calculations. Don’t get too ‘hung up’ on this though. If you can make sense of the actual script being used for the calculation then just put it to the test on a demo account or something like that. The point I’m trying to make is that my % gains are being made using ADX/ADXR (used correctly or incorrectly as per my posts of yesterday) so even if Delta’s is incorrect (which I’m confident it’s not) then it’s certainly working for me anyway. If your ADX/ADXR is indeed wrong at Alpari you’ll very quickly find out by using it to to pick your systems and instruments or pairs to trade i.e. if it’s right then you have to get roughly the same results as another trader using another broker. I know that’s not the ‘definitive’ answer that you’d like to hear but there have been times where I’ve struggled to get the same or similar results as Wilder in the book and only with time have I figured out the reason(s) why but it’d not simply let it keep me away from trading the systems. Also: you should be able to see from the chart whether or not an instrument or pair is trading in a range or trending and compare that to your ADX indicator. You should also be able to see the correlation between the +DI and -DI crossings as well. I mean: I’ve just looked at GBP/JPY (daily) at Alpari and even although the actual values differ from mine the ADX quite correctly signals the end and / or the change in direction of the trend and I can also see that where +DI has crossed above -DI I would have / could have gone long (and visa versa for short trades of course).
Edit:
ON THE OTHER HAND (I really could have been a ‘Chief Analyst’ or ‘Chief Economist’ don’t you think???):
I’ve taken some more time now to compare Alpari’s ADX with Delta’s (and GCI’s) and I have to say that sometimes the values are very close BUT OTHER TIMES they really ARE miles apart and I can see how / why this could / would be frustrating. I suppose it’s time for me to reconstruct my original DMI Work Sheet and do some manual testing!!! Put this ‘to bed’ (which is where I’m going now) once and for all!!!