/*********************************************************
Alexis C. Montenegro © November 2006                      
Use and/or modify this code freely. If you redistribute it
please include this and/or any other comment blocks and a 
description of any changes you make.                      
**********************************************************/

// NOTE:                                                                          
// This efs requires amStudies.efsLib in the FunctionLibrary folder.              
// If you do not have this file you can download it at the link below.            
// http://share.esignal.com/groupcontents.jsp?folder=Formulas-Libraries&groupid=10

var fpArray = new Array();

function preMain() {
    setPriceStudy(true);
    setStudyTitle("VWAP");
    setCursorLabelName("VWAP",0);
    setDefaultBarFgColor(Color.blue,0);
    setPlotType(PLOTTYPE_SQUAREWAVE,0);
    setDefaultBarThickness(1,0);
    var x=0;
    fpArray[x] = new FunctionParameter("StartTime", FunctionParameter.STRING);
    with(fpArray[x++]){
        setName("Start Time");
        setDefault(930);
	}
    fpArray[x] = new FunctionParameter("Symbol", FunctionParameter.STRING);
    with(fpArray[x++]){
        setDefault();
	}
	fpArray[x] = new FunctionParameter("Interval", FunctionParameter.STRING);
	with(fpArray[x++]){
        setDefault();
    }
    fpArray[x] = new FunctionParameter("Params", FunctionParameter.BOOLEAN);
	with(fpArray[x++]){
        setName("Show Parameters");
        setDefault(false);
    }
}

var amLib = addLibrary("amStudies.efsLib");
var bInit = false
var xVWAP = null;

function main(StartTime,Symbol,Interval,Params) {
    if(bInit==false){
        with( amLib ) {
            if(Symbol == null) Symbol = getSymbol();
            if(Interval == null) Interval = getInterval();
            var vSymbol = Symbol+","+Interval;
            xVWAP = getSeries(amVWAP2(StartTime+"",sym(vSymbol)));
            setShowTitleParameters(eval(Params));
            bInit=true;
        }
    }
    return xVWAP;
}