BB Flat SW

[eSignal]

File Name: BBflat_sw.efs

Description:
BBFlat SW

Formula Parameters:
Length : 9
Deviation : 1.5
Source of Price : Close
MA Type : SMA


Notes:



Download File:
BBflat_sw.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:        
    BBFlat SW
Version:            1.0  08/26/2009
 
Formula Parameters:                     Default:
    Length                              9
    Deviation                           1.5
    Source of Price                     Close
    MA Type                             SMA
   
Notes:
    
**********************************/
var fpArray = new Array();
var bInit = false;

function preMain(){
    setPriceStudy(false);
    setShowCursorLabel(true);
    setShowTitleParameters(false);
    setStudyTitle("BBFlat SW");
    setCursorLabelName("BBFlatP", 0);
    setDefaultBarFgColor(Color.red, 0);
    setPlotType(PLOTTYPE_LINE, 0);
    setCursorLabelName("BBFlatM", 1);
    setDefaultBarFgColor(Color.red, 1);
    setPlotType(PLOTTYPE_LINE, 1);
    setCursorLabelName("BBFlat", 2);
    setDefaultBarFgColor(Color.green, 2);
    setPlotType(PLOTTYPE_LINE, 2);
    var x = 0;
    fpArray[x] = new FunctionParameter("Length", FunctionParameter.NUMBER);
    with(fpArray[x++]) {
        setName("Length");
        setLowerLimit(1);
        setDefault(9);
    }    
    fpArray[x] = new FunctionParameter("Deviation", FunctionParameter.NUMBER);
    with(fpArray[x++]) {
        setName("Deviation");
        setDefault(1.5);
    }        
    fpArray[x] = new FunctionParameter("sPrice", FunctionParameter.STRING);
    with(fpArray[x++]){
        setName("Source of Price");
        addOption("open"); 
        addOption("high");
        addOption("low");
        addOption("close");
        addOption("hl2");
        addOption("hlc3");
        addOption("ohlc4"); 
        setDefault("close"); 
    }    
    fpArray[x] = new FunctionParameter("sMAType", FunctionParameter.STRING);
    with(fpArray[x++]) {
        setName("MA Type");
        addOption("sma");
        addOption("ema");
        addOption("wma");
        addOption("vwma");
        setDefault("sma");
    }
}

var xBBFlatP = null;
var xBBFlatM = null;
var xBBFlat = null;

function main(Length, Deviation, sPrice, sMAType) {
var nBarState = getBarState();
var nBBFlatP = 0;
var nBBFlatM = 0;
var nBBFlat = 0;
    if (nBarState == BARSTATE_ALLBARS) {
        if(Length == null) Length = 9;
        if(Deviation == null) Deviation = 1.5;        
        if(sPrice == null) sPrice = "close";
        if(sMAType == null) sMAType = "sma";
    }
    if (bInit == false) {
        addBand(0, PS_SOLID, 1, Color.black, "ZeroLine");
        xBBFlatP = efsInternal("Calc_BBFlat", Length, Deviation, sPrice, sMAType)
        xBBFlatM = getSeries(xBBFlatP, 1);
        xBBFlat = getSeries(xBBFlatP, 2);
        bInit = true;
    }
    nBBFlatP = xBBFlatP.getValue(0);
    nBBFlatM = xBBFlatM.getValue(0);
    nBBFlat = xBBFlat.getValue(0);
    if (nBBFlatP == null || nBBFlat == null) return;
    return new Array(nBBFlatP, nBBFlatM, nBBFlat);
}

var bSecondInit = false;
var xPrice = null;
var xMA = null;
var xStdDev = null;

function Calc_BBFlat(Length, Deviation, sPrice, sMAType) {
var nStdP = 0;
var nStdC = 0;
    if (!bSecondInit) {
        xPrice = eval(sPrice)();
        xMA = eval(sMAType)(Length, xPrice);
        xStdDev = efsInternal("Calc_StdDev", Length, xMA, xPrice);
        bSecondInit = true;
    }
    nStdP = xStdDev.getValue(0);
    if (nStdP == null) return;
    nStdP = Deviation * nStdP;
    nStdC = xPrice.getValue(0) - xMA.getValue(0);
    return new Array(nStdP, -nStdP, nStdC);
}

function Calc_StdDev(LookBack, xPrice1Avg, xPrice1) {
var nRes = 0;
    if (xPrice1Avg.getValue(0) == null) return;
    for (var i = 0; i < LookBack; i++) {
        nRes += Math.pow(xPrice1.getValue(-i) - xPrice1Avg.getValue(0),2);
    }
    nRes = Math.sqrt(nRes / LookBack);
    if (nRes == null) nRes = 1;
    return nRes;
}