MT4 ZigZag explanation

Ok, I'm looking at the Zig Zag indicator and I'm going to use it, but I don't understand what 2 of the variables are for.

ExtDeviation and ExtBackstep.

I've looked at the code and I must either be tired or am just not seeing it. I can't discertain what they are for or what they do.

ExtDepth is the number of periods for the iHighest and iLowest functions to get the highs and lows. I get that much, at least.

Thanks.
-Non.

http://www.forex-tsd.com/metatrader-....html#post8792

I found this answer within 2 minutes, by using forex-tsd's search facility. I can only assume that it's valid, and also that it applies to the same ZigZag indy that you're referring to. If not, there plenty more info at forex-tsd on a wide number of Zigzag type indicators.

Thanks. That answered it!

Well, I didn't find the explanation (on TSD) very understandable and can't find any other results on these 2 forums, so I decided to figure this out. Apparently I am the only one who doesn't (didn't) understand it. Here's what I have determined:

If you use the parameters 12/5/3, and let's just talk about the Highs for now, this means if your last point is a Low, you can have a new higher High in less than 12 bars (ExtDepth), but you can not have a new lower high in less than 12 bars (or 13 really). The ExtDeviation (5) seems virtually useless since the only time it comes in is when ZZ checks if the current High is higher than the last High or between 1 and 4 micropips lower, and then all that happens is it checks the last 3 prior bars (ExtBackstep) to see if they are lower Highs than current and erase any HighMapBuffer values found. So it seems the only really important parameter is the ExtDepth which you use to decide how ofter to look for lower Highs or higher Lows, since you can have a High on one bar, a lower Low on the next, a higher High on the next, and so on.

Now I'm going to try to forget how much time I've wasted trying to figure that out. Hope it helps someone else.

Very Useful. Thanks.

Thanks for the explanation. I found it very useful as well.

thank you