Force Index

ForceIndex.efs  

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File Name: ForceIndex.efs

Description:
Force Index

Formula Parameters:

• XLen1 : 3
• XLen3 : 13

Notes:
This Indicator plots the Force Index as described by Dr. Alexander Elder in "Trading For a Living." The ForceIndex indicator relates price to volume by multiplying net change and volume. ForceIndex is calculated using the following equation: 

• ForceIndex = Volume(today) * (Close(this period) - Close(last period))
• ForceIndex is typically presented as two smoothed averages (slow and fast) to avoid false signals.

Download File:
ForceIndex.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:        
    Force Index
    
Version:            1.0  04/15/2009

Formula Parameters:                     Default:
    XLen1                               3
    XLen3                               13
Notes:
    This Indicator plots the Force Index as described by Dr. Alexander 
    Elder in "Trading For a Living." The ForceIndex indicator relates 
    price to volume by multiplying net change and volume. ForceIndex is 
    calculated using the following equation:
    ForceIndex = Volume(today) * (Close(this period) - Close(last period))
    ForceIndex is typically presented as two smoothed averages (slow and fast) 
    to avoid false signals. 
**********************************/
var fpArray = new Array();
var bInit = false;

function preMain() {
    setStudyTitle("Force Index");
    setCursorLabelName("FastAvg", 0);
    setCursorLabelName("SlowAvg", 1);
    setDefaultBarFgColor(Color.blue, 0);
    setDefaultBarFgColor(Color.red, 1);
    setPlotType(PLOTTYPE_HISTOGRAM, 0);
    var x = 0;
    fpArray[x] = new FunctionParameter("XLen1", FunctionParameter.NUMBER);
    with(fpArray[x++]) {
        setLowerLimit(1);
        setDefault(3);
    }
    fpArray[x] = new FunctionParameter("XLen2", FunctionParameter.NUMBER);
    with(fpArray[x++]) {
        setLowerLimit(1);
        setDefault(13);
    }
}

var xForce1 = null;
var xForce2 = null;

function main(XLen1, XLen2) {
var nBarState = getBarState();
var nForce1 = 0;
var nForce2 = 0;
    if (nBarState == BARSTATE_ALLBARS) {
        if (XLen1 == null) XLen1 = 3;
        if (XLen2 == null) XLen2 = 13;
    }
    
    if (bInit == false) {
        addBand(0, PS_SOLID, 1, Color.green, 1);
        xForce1 = efsInternal("Calc_Force_Index", XLen1, XLen2);
        xForce2 = getSeries(xForce1, 1);
        bInit = true;
    }
    nForce1 = xForce1.getValue(0);
    nForce2 = xForce2.getValue(0);
   
    return new Array(nForce1, nForce2);
}

var xValue = null;
var xSMA1 = null;
var xSMA2 = null;
var bSecondInit = false;

function Calc_Force_Index(nLen1, nLen2) {
var nRes = 0;
var nSMA1 = 0;
var nSMA2 = 0;
    if (bSecondInit == false) {
        xValue = efsInternal("Calc_Value");
        xSMA1 = ema(nLen1, xValue);
        xSMA2 = ema(nLen2, xValue);
        bSecondInit = true;
    }
    nSMA1 = xSMA1.getValue(0);
    nSMA2 = xSMA2.getValue(0);
    if (nSMA1 == null || nSMA2 == null) return;
    return new Array(nSMA1, nSMA2);
}

function Calc_Value() {
var nRes = 0;
    nRes = volume(0) * (close(0) - close(-1));
    if (nRes == null) return;
    return nRes;
}