/*********************************************************
Alexis C. Montenegro © January 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.                      
**********************************************************/

var fpArray = new Array();

function preMain() {
    setPriceStudy(false);
    setStudyTitle("Chaikin Oscillator");
    setCursorLabelName("CO");
    setDefaultBarFgColor(Color.blue);
    setDefaultBarThickness(1);
	setPlotType(PLOTTYPE_LINE);
	var x=0;
    fpArray[x] = new FunctionParameter("Fast", FunctionParameter.NUMBER);
	with(fpArray[x++]){
        setLowerLimit(1);		
        setDefault(3);
    }
    fpArray[x] = new FunctionParameter("Slow", FunctionParameter.NUMBER);
	with(fpArray[x++]){
        setLowerLimit(1);		
        setDefault(10);
    }
    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("Hist", FunctionParameter.BOOLEAN);
	with(fpArray[x++]){
        setName("Plot as Histogram");
        setDefault(false);
    }
    fpArray[x] = new FunctionParameter("Params", FunctionParameter.BOOLEAN);
	with(fpArray[x++]){
        setName("Show Parameters");
        setDefault(false);
    }
    
}

var bInit = false;
var xCOsc  = null;

function main(Fast,Slow,Symbol,Interval,Hist,Params) {
    if(bInit == false){
        if(Symbol == null) Symbol = getSymbol();
        if(Interval == null) Interval = getInterval();
        var vSymbol = Symbol+","+Interval;
        xCOsc = getSeries(efsInternal("calcCOsc",Fast,Slow,(sym(vSymbol))));
        if(Hist == true) setPlotType(PLOTTYPE_HISTOGRAM);
        addBand(0, PS_SOLID, 1, Color.black,"0");
        setShowTitleParameters(eval(Params));
        bInit = true;
    }
    return xCOsc;
}

var xInit = false;
var xFast = null;
var xSlow  = null;

function calcCOsc(fast,slow,source){
    if(xInit == false){
        xFast = ema(fast,accDist());
        xSlow = ema(slow,accDist());
        xInit = true;
    }
    if(getCurrentBarCount()<slow) return;    
	return (xFast.getValue(0)-xSlow.getValue(0));
}