2010 Jan: The Vortex Indicator

[eSignal]

File Name: Vortex.efs

Description:
The Vortex Indicator

Formula Parameters:
Length of Vortex : 14


Notes:
The related article is copyrighted material. If you are not a subscriber
of Stocks & Commodities, please visit www.traders.com.



Download File:
Vortex.efs



EFS Code:

/*********************************
Provided By:  
    eSignal (Copyright c eSignal), a division of Interactive Data 
    Corporation. 2009. 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:        
    The Vortex Indicator
Version:            1.01  12/29/2009

Formula Parameters:                     Default:
    Length of Vortex                    14    
Notes:
    The related article is copyrighted material. If you are not a subscriber
    of Stocks & Commodities, please visit //www.traders.com.

**********************************/
var fpArray = new Array();
var bInit = false;
var bVersion = null;

function preMain() {
    setPriceStudy(false);
    setShowCursorLabel(true);
    setShowTitleParameters(false);
    setStudyTitle("Vortex");
    setCursorLabelName("+VI", 0);
    setDefaultBarFgColor(Color.blue, 0);
    setPlotType(PLOTTYPE_LINE, 0);
    setDefaultBarThickness(2, 0);
    setCursorLabelName("-VI", 1);
    setDefaultBarFgColor(Color.red, 1);
    setPlotType(PLOTTYPE_LINE, 1);
    setDefaultBarThickness(2, 1);
    askForInput();
    var x=0;
    fpArray[x] = new FunctionParameter("LengthVortex", FunctionParameter.NUMBER);
    with(fpArray[x++]){
        setName("Length of Vortex");
        setLowerLimit(1);        
        setDefault(14);
    }    
}

var xVortexPlus = null;
var xVortexMinus = null;

function main(LengthVortex) {
var nBarState = getBarState();
var nVortexP = 0;
var nVortexM = 0;
    if (bVersion == null) bVersion = verify();
    if (bVersion == false) return;   
    if (nBarState == BARSTATE_ALLBARS) {
        if (LengthVortex == null) LengthVortex = 14;
    }    
    if (!bInit) { 
        xVortexPlus = efsInternal("Calc_Vortex", LengthVortex);
        xVortexMinus = getSeries(xVortexPlus, 1);
        bInit = true; 
    }
    nVortexP = xVortexPlus.getValue(0);
    nVortexM = xVortexMinus.getValue(0);
    if (nVortexP == null || nVortexM == null) return;
    return new Array(nVortexP, nVortexM);
}

var bSecondInit = false;
var xVMm = null;
var xVMp = null;
var xVM_TrueRange = null;

function Calc_Vortex(LengthVortex) {
var nVortexP = 0;
var nVortexM = 0;
var nVMpSum = 0;
var nVMmSum = 0;
var nTRSum = 0;
var i = 0;
    if (bSecondInit == false) {
        xVMp = efsInternal("Calc_VM_TR");
        xVMm = getSeries(xVMp, 1);
        xVM_TrueRange = getSeries(xVMp, 2);
        bSecondInit = true;
    }
    if (xVMp.getValue(-LengthVortex) == null || xVM_TrueRange.getValue(-LengthVortex) == null) return;
    for (i = LengthVortex; i >= 0; i--) {
        nVMpSum += xVMp.getValue(-i);
        nVMmSum += xVMm.getValue(-i);
        nTRSum += xVM_TrueRange.getValue(-i);
    }
    if (nTRSum != 0) {
        nVortexP = nVMpSum / nTRSum;
        nVortexM = nVMmSum / nTRSum;
    }
    return new Array(nVortexP, nVortexM);
}

var bThirdInit = false;
var xHigh = null;
var xLow = null;
var xClose = null;

function Calc_VM_TR() {
var nVMp = 0;
var nVMm = 0;
var nH1 = 0;
var nH = 0;
var nL1 = 0;
var nL = 0;
var nC1 = 0;
var nTR = 0;
    if (bThirdInit == false) {
        xHigh = high();
        xLow = low();
        xClose = close();
        bThirdInit = true;
    }
    nH1 = xHigh.getValue(-1);
    nH = xHigh.getValue(0);
    nL1 = xLow.getValue(-1);
    nL = xLow.getValue(0);
    nC1 = xClose.getValue(-1);
    if (nH1 == null) return;
    nVMp = Math.abs(nH - nL1);
    nVMm = Math.abs(nL - nH1);
    nTR = Math.max(nH - nL, Math.abs(nH - nC1));
    nTR = Math.max(nTR, Math.abs(nL - nC1))
    return new Array(nVMp, nVMm, nTR);
}

function verify() {
    var b = false;
    if (getBuildNumber() < 779) {
        drawTextAbsolute(5, 35, "This study requires version 8.0 or later.", 
            Color.white, Color.blue, Text.RELATIVETOBOTTOM|Text.RELATIVETOLEFT|Text.BOLD|Text.LEFT,
            null, 13, "error");
        drawTextAbsolute(5, 20, "Click HERE to upgrade.@URL=http://www.esignal.com/download/default.asp", 
            Color.white, Color.blue, Text.RELATIVETOBOTTOM|Text.RELATIVETOLEFT|Text.BOLD|Text.LEFT,
            null, 13, "upgrade");
        return b;
    } else {
        b = true;
    }
    return b;
}