Chaikin Volatility

ChaikinVolatility.efs  
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File Name: ChaikinVolatility.efs

Description:
Chaikin Volatility

Formula Parameters:

• Length: 10
• ROC Length: 12
• Price 1 Data To Use: High
• Price 2 Data To Use: Low

Notes:
Chaikin's Volatility indicator compares the spread between a security's high and low prices. It quantifies volatility as a widening of the range between the high and the low price.

Download File:
ChaikinVolatility.efs


EFS Code:

/*********************************
Provided By:  
    eSignal (Copyright c eSignal), a division of Interactive Data 
    Corporation. 2008. All rights reserved. This sample eSignal 
    Formula Script (EFS) is for educational purposes only and may be 
    modified and saved under a new file name.  eSignal is not responsible
    for the functionality once modified.  eSignal reserves the right 
    to modify and overwrite this EFS file with each new release.

Description:        
    Chaikin Volatility 

Version:            1.0  11/10/2008

Formula Parameters:                     Default:
    Length                                  10
    ROC Length                              12
    Price 1 Data To Use                    High
    Price 2 Data To Use                    Low    

Notes:
    Chaikin's Volatility indicator compares the spread between a security's
    high and low prices. It quantifies volatility as a widening of the range
    between the high and the low price.

**********************************/


var fpArray = new Array();
var bInit = false;

function preMain() {
    setPriceStudy(false)
    setStudyTitle("Chaikin Volatility");
    setCursorLabelName("Chaikin Volatility", 0);
    setDefaultBarFgColor(Color.blue, 0);
    setPlotType(PLOTTYPE_LINE,0);
    setDefaultBarThickness(1,0);

    var x=0;
    fpArray[x] = new FunctionParameter("Length", FunctionParameter.NUMBER);
    with(fpArray[x++]){
        setLowerLimit(1);        
        setDefault(10);
    }

    fpArray[x] = new FunctionParameter("ROCLen", FunctionParameter.NUMBER);
    with(fpArray[x++]){
        setName("ROC Length");
        setLowerLimit(1);        
        setDefault(12);
    }

    fpArray[x] = new FunctionParameter("Price1", FunctionParameter.STRING);
    with(fpArray[x++]){
        setName("Price 1 Data To Use");
        addOption("open"); 
        addOption("high");
        addOption("low");
        addOption("close");
        addOption("hl2");
        addOption("hlc3");
        addOption("ohlc4"); 
        setDefault("high"); 
    }

    fpArray[x] = new FunctionParameter("Price2", FunctionParameter.STRING);
    with(fpArray[x++]){
        setName("Price 2 Data To Use");
        addOption("open"); 
        addOption("high");
        addOption("low");
        addOption("close");
        addOption("hl2");
        addOption("hlc3");
        addOption("ohlc4"); 
        setDefault("low"); 
    }
}

var xROC_EMA = null;
var xPrice1 = null;
var xPrice2 = null;
var xPrice = null;

function main(Price1, Price2, Length, ROCLen) {
var nState = getBarState();
var nROC = 0;

    if (nState == BARSTATE_ALLBARS) {
        if (Price1 == null) Price1 = "high";
        if (Price2 == null) Price2 = "low";
        if (Length == null) Length = 10;
        if (ROCLen == null) ROCLen = 12;
    }
    
    if ( bInit == false ) { 
        xPrice1 = eval(Price1)();
        xPrice2 = eval(Price2)();        
        xPrice = efsInternal("Calc_Price", xPrice1, xPrice2)
        xROC_EMA = roc(ROCLen, ema(Length, xPrice));
        bInit = true; 
    } 

    if (getCurrentBarCount() < Math.max(Length, ROCLen)) return;

    nROC = xROC_EMA.getValue(0);
    return nROC;
}

function Calc_Price(xPrice1, xPrice2) {
var nRes = 0;
    nRes = xPrice1.getValue(0) - xPrice2.getValue(0);
    if (nRes == null) nRes = 1;
    return nRes;
}