2014 Aug: The Quotient Transform by John F. Ehlers

[eSignal]

File Name: EarlyOnsetTrendIndicator.efs

Description:
The Quotient Transform by John F. Ehlers

Formula Parameters:

EarlyOnsetTrendIndicator.efs
LPPeriod: 30
K: 0.85


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

Download File:
EarlyOnsetTrendIndicator.efs


EarlyOnsetTrendIndicator.efs


EFS Code:

/*********************************
Provided By:  
    Interactive Data Corporation (Copyright В© 2014) 
    All rights reserved. This sample eSignal Formula Script (EFS)
    is for educational purposes only. Interactive Data Corporation
    reserves the right to modify and overwrite this EFS file with 
    each new release. 

Description:        
    The Quotient Transform by John F. Ehlers 

Formula Parameters:                     Default:
LPPeriod                                30
K                                       0.85 

Version:            1.00  09/06/2014

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();

function preMain()
{   
    setStudyTitle("EarlyOnsetTrendIndicator");
    setDefaultBarFgColor(Color.red);   
    
    addBand(0, PS_SOLID, 1, Color.grey);
    
    var x = 0;

    fpArray[x] = new FunctionParameter("fpLPPeriod", FunctionParameter.NUMBER);
    with(fpArray[x++])
    {
        setName("LPPeriod");
        setDefault(30);
        setLowerLimit(1);
    }

    fpArray[x] = new FunctionParameter("fpK", FunctionParameter.NUMBER);
    with(fpArray[x++])
    {
        setName("K");
        setDefault(0.85);
        setLowerLimit(-1);
        setUpperLimit(1);
    }
}

var bInit = false;
var bVersion = null;

xHP = null;
xFilt = null;
xPeak = null;
xX = null;
xQuotient = null;

function main(fpLPPeriod, fpK) 
{
    if (bVersion == null) bVersion = verify();
    if (bVersion == false) return;
    
    if (!bInit)
    {      
        xHP = efsInternal("Calc_HP");
        xFilt = efsInternal("Calc_Filt", xHP, fpLPPeriod);
        xPeak = efsInternal("Calc_Peak", xFilt);
        xX = efsInternal("Calc_X", xPeak, xFilt);
        xQuotient = getSeries(efsInternal("Calc_Quotient", xX, fpK));
   
        bInit = true;
    }
  
    return xQuotient;
}

var xClose = null;
var nAlpha1 = 0;

function Calc_HP()
{
    if (getBarState() == BARSTATE_ALLBARS)
    {
        xClose = close();

        nAlpha1 = (Math.cos((0.707 * 360 / 100) * (Math.PI / 180)) +
                   Math.sin((0.707 * 360 / 100) * (Math.PI / 180))  - 1) / 
                   Math.cos((0.707 * 360 / 100) * (Math.PI / 180));

    } 

    var nClose_0 = xClose.getValue(0);
    var nClose_1 = xClose.getValue(-1);
    var nClose_2 = xClose.getValue(-2);

    if (nClose_0 == null || nClose_1 == null || nClose_2 == null)
        return;

    var arrRefHP = ref(-1, -2);

    var nHP_1 = arrRefHP[0];
    var nHP_2 = arrRefHP[1];   

    var nReturnValue = (1 - nAlpha1 / 2) * (1 - nAlpha1 / 2) * (nClose_0 - 2 * nClose_1 + nClose_2) +
                       2 * (1 - nAlpha1) * nHP_1 -
                       (1 - nAlpha1) * (1 - nAlpha1) * nHP_2;
          
    return nReturnValue;
}

var nA1 = 0;
var nB1 = 0;
var nC1 = 0;
var nC2 = 0;
var nC3 = 0;

function Calc_Filt(xHP, nLPPeriod)
{
    if (getBarState() == BARSTATE_ALLBARS)
    {
        nA1 = Math.exp(-1.414 * 3.14159 / nLPPeriod);
        nB1 = 2 * nA1 * Math.cos((1.414 * 180 / nLPPeriod) * (Math.PI / 180));
        nC2 = nB1;
        nC3 = -nA1 * nA1;
        nC1 = 1 - nC2 - nC3; 
    } 

    var nHP_0 = xHP.getValue(0);
    var nHP_1 = xHP.getValue(-1);

    if (nHP_0 == null || nHP_1 == null)
        return;

    var arrRefFilt = ref(-1, -2);

    var nFilt_1 = arrRefFilt[0];
    var nFilt_2 = arrRefFilt[1];   

    var nReturnValue = nC1 * (nHP_0 + nHP_1) / 2 + nC2 * nFilt_1 + nC3 * nFilt_2;
          
    return nReturnValue;
}

function Calc_Peak(xFilt)
{
    var nFilt = xFilt.getValue(0);

    if (nFilt == null)
        return;

    var nPeak_1 = ref(-1);
    
    var nPeak = 0.991 * nPeak_1;

    if (Math.abs(nFilt) > nPeak)
        nPeak = Math.abs(nFilt);

    var nReturnValue = nPeak;

    return nReturnValue;
}

function Calc_X(xPeak, xFilt)
{
    var nPeak = xPeak.getValue(0);
    var nFilt = xFilt.getValue(0);

    if (nPeak == null || nFilt == null)
        return;
    
    var nReturnValue = 0;
     
    if (nPeak != 0)
        nReturnValue = nFilt / nPeak; 

    return nReturnValue;
}

function Calc_Quotient(xX, nK)
{
    var nX = xX.getValue(0);
   
    if (nX == null)
        return;
    
    var nReturnValue = (nX + nK) / (nK * nX + 1);

    return nReturnValue;
}

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;
}