Hi Paul

Here's the beginnings of an indicator that might do what you want. I've used PeakBars() and TroughBars() to calculate the lookback range over which to calculate Volume rather than use Zig() for that purpose. The down side is that my indicator only caters for a percent-based Zig() simulation - I'd need to use the Zig() function directly in order to incorporate a points-based capability. However this is only a demonstration and you can modify the code however you wish. You'll need the 188 KB version of the Forum DLL installed and named Forum.DLL for this formula to work as is. If you already have the DLL but under a slightly different name then just change the DLL name in the last line of my code to as necessary. The DLL is available as a download in the Files section of this forum.

{Zig Zag Volume}
D:=Input("Zig Zag Volume Data Array, 1=O 2=H 3=L 4=C",1,4,4);
M:=Input("Zig Zag Minimum % Change",0,999,5);
K:=If(D=1,O,If(D=2,H,If(D=3,L,C)));
A:=PeakBars(1,K,M);
B:=TroughBars(1,K,M);
F:=Min(A,B)+1;
ExtFml("Forum.Sum",V,F);

Roy