"Volume Weighted Average Price. A of the price at which the of a given day's trading in a given security took place. Calculated by taking the weighted average of the prices of each trade. The is used by institutional traders, who often break a given trade into multiple transactions."
The VWAP for a stock is calculated by adding the dollars traded for every transaction in that stock ("price" x "number of shares traded") and dividing the total shares traded. A VWAP is computed from the Open of the market to the market Close, AND is calculated by Volume weighting all transactions during this time period.
VWAP, or Volume Weighted Average Price is a tool used by some traders, I first learned of it from Brian Shannon who trades stocks. This won't work for forex since there is no volume.
There are a few different ways of displaying this in Amibroker. It can be a simple line like a moving average, this is the most common way pro's use it. Amibroker has a function to display it behind price, look in the help for these two functions with examples;
eTokes Blog post on VWAP
I suggest reading his post, as well as Brian's post on VWAP, links below. eToke used a vertical "study" line drawn on the chart. This might give you an error on your chart if there is no line drawn. Here is his code with a little fix for this problem (adding "Nz");
Plot VWAP starting at a horizontal study line (Study ID set to ST)
//VWAP since last change in sentiment
TurningPoint = IIf(Nz(Study(“ST”,GetChartID())==0,1,0));
BarsSinceLastTurn = 1 + BarsSince(TurningPoint==1);
StartBar = ValueWhen(TurningPoint==1, BarIndex());
RunVolume = Sum(V,BarsSinceLastTurn);
IIf (BarIndex() >= StartBar, MTVWAP = Sum (C * V, BarsSinceLastTurn ) / RunVolume,0);
Plot (MTVWAP,”MTVWAP”,colorPink, styleLine);
Other ways to plot VWAP
Plot VWAP starting at selector line
This is another way, it will display the VWAP starting from where your selector line is placed. I use it for short term trading to see where all the volume is, makes finding support / resistance a bit easier when working with breakout.
segments = IIf(SelectedValue(BarIndex()) == BarIndex(), 1, 0);
PlotVAPOverlayA( segments , 300, 50, ParamColor("Color", colorDarkGrey ), 6 );
Bars_so_far_today = 1 + BarsSince( Day() != Ref(Day(), -1));
StartBar = ValueWhen(TimeNum() == 093000, BarIndex());
TodayVolume = Sum(V,Bars_so_far_today);
IIf (BarIndex() >= StartBar, VWAP = Sum (C * V, Bars_so_far_today ) / TodayVolume,0);
Plot (VWAP,"VWAP",colorOrange, styleThick);
Other links on VWAP
VWAP link 1
VWAP link 2