Zig Zag Help

Hi Guys,

In the zig zag indicator what do these three inputs mean

ExtDepth
ExtDeviation
ExtBackStep

Can somebody please explain this to me

Cheers
B

These are excerpts from NewDigital at the TSD forum.
Warning! You may get dizzy from so many ZZ's available.
Regards.

http://www.forex-tsd.com/metatrader-...indicator.html

"I am not expert on zigzag but I think that it is seaching the low (for example) from the current bar up to ExtDepth periods back (ExtDepth bars back). If the new Low was not found the indicator returns zero (no new Low).

Code:
val=Low[Lowest(NULL,0,MODE_LOW,ExtDepth,shift)]; if(val==lastlow) val=0.0;

If the new Low was found so the indicator check this current new Low with the previous Low and if the current new Low is higher of the previous Low on the ExtDeviation point (if ExtDeviation=5 so if new Low is higher previous Low on 5 point) the indicator will not consider this new Low as a Low and we will still have the previous one:

Code:
if((Low[shift]-val)>(ExtDeviation*Point)) val=0.0;

What is ExtBackstep?
If we have several equal Lows (with the same value) so the indicator will consider the last one only.

If the current Low is higher than previous one but not more higher then previos Low plus ExtDeviation so we have the following:

Code:
for(back=1; back<=ExtBackstep; back++)