Need Help to apply Bollinger Bands to a DMA

[steven723]

I need help in applying Bollinger bands to a displaced moving average. I have no idea how to do this and would greatly appreciate some help anybody could give me as I am new to the Java language. Below is the code for the displaced moving average I want to apply a Standard Deviation to:

function preMain() {
setPriceStudy(true);
setStudyTitle("25X5 DMA");
//setPlotType(PLOTTYPE_LINE);

setCursorLabelName("25X5 DMA", 0);
setDefaultBarThickness(1, 0);
setDefaultBarFgColor(Color.green, 0);
}

function main() {

var v25x5dma = new MAStudy(25, 5, "Close", MAStudy.SIMPLE);

return v25x5dma.getValue(MAStudy.MA)

}

[buzzhorton]

I think this should get you close.

Perhaps someone else can explain why the DMA line plots differently from the middle bb line?!!?

Shouldn't it be the same if the DMA is the input?

var fpArray = new Array();

function preMain() {

    setPriceStudy(true);

    setStudyTitle("TRO_DMABB"); 

    setCursorLabelName("25x5dma ",0);
    setCursorLabelName("UprBB", 1);
    setCursorLabelName("BasBB", 2);
    setCursorLabelName("LwrBB", 3);

    setDefaultBarFgColor(Color.purple, 0);
    setDefaultBarFgColor(Color.blue, 1);
    setDefaultBarFgColor(Color.red, 2);
    setDefaultBarFgColor(Color.blue, 3);

    setPlotType(PLOTTYPE_LINE,0);
    setPlotType(PLOTTYPE_LINE,1);
    setPlotType(PLOTTYPE_LINE,2);
    setPlotType(PLOTTYPE_LINE,3);

    setDefaultBarThickness(1,0);
    setDefaultBarThickness(1,1);
    setDefaultBarThickness(1,2);
    setDefaultBarThickness(1,3);
 
    var iAlert = new FunctionParameter("iAlert", FunctionParameter.BOOLEAN);
    iAlert.setDefault( true );

    var iColor01 = new FunctionParameter("iColor01", FunctionParameter.COLOR);
        iColor01.setDefault( Color.green );

    var iColor02 = new FunctionParameter("iColor02", FunctionParameter.COLOR);
        iColor02.setDefault( Color.red );


    var iColor03 = new FunctionParameter("iColor03", FunctionParameter.COLOR);
        iColor03.setDefault( Color.cyan );

    var iColor04 = new FunctionParameter("iColor04", FunctionParameter.COLOR);
        iColor04.setDefault( Color.magenta );


// BUTTON CODE

    var iButtonX = new FunctionParameter("iButtonX", FunctionParameter.NUMBER);
    iButtonX.setDefault( 1 ); 

    var iButtonY = new FunctionParameter("iButtonY", FunctionParameter.NUMBER);
    iButtonY.setDefault( 20 ); 

    var iFontSize = new FunctionParameter("iFontSize", FunctionParameter.NUMBER);
        iFontSize.setName("Button Font Size");
    iFontSize.setDefault( 10 ); 


    var x=0;
    fpArray[x] = new FunctionParameter("Length", FunctionParameter.NUMBER);
    with(fpArray[x++]){
        setLowerLimit(1);        
        setDefault(20);
    }
    fpArray[x] = new FunctionParameter("StdDev", FunctionParameter.NUMBER);
    with(fpArray[x++]){
        setLowerLimit(0);    
        setDefault(2);
    }
    fpArray[x] = new FunctionParameter("Source", FunctionParameter.STRING);
    with(fpArray[x++]){
        addOption("open"); 
        addOption("high");
        addOption("low");
        addOption("close");
        addOption("hl2");
        addOption("hlc3");
        addOption("ohlc4"); 
        setDefault("close"); 
    }
    fpArray[x] = new FunctionParameter("Symbol", FunctionParameter.STRING);
    with(fpArray[x++]){
        setDefault();
    }
    fpArray[x] = new FunctionParameter("Interval", FunctionParameter.STRING);
    with(fpArray[x++]){
        setDefault();
    }

}


// BUTTON CODE

var bEdit         = true; 
var nColWidth      = 0;
var nRowThickness = 1;
var nFontSize     = 10; 

var tInit  = false ;

var v25x5dma = null ;
 
var x25x5dma = null ;

var Symbol   = null;
var Interval = null;
var Source = null;

var bupperBB  = null ;
var bmiddleBB = null ;
var blowerBB  = null ;

askForInput();


function main( iAlert,     iFontSize, iButtonX, iButtonY) {

// BUTTON CODE

    if(getBarState() == BARSTATE_ALLBARS) {
        drawTextPixel(  iButtonX , iButtonY, " $TRO_DMABB @URL=EFS:editParameters", Color.white, Color.green, 
            Text.RELATIVETOLEFT|Text.RELATIVETOBOTTOM|Text.ONTOP|Text.BOLD|Text.BUTTON, 
            "Comic Sans MS", 13, "UpExp"); 
       
    return null;
    }




if(  tInit  == false ) {


        if(Symbol == null)   Symbol = getSymbol();
        if(Interval == null) Interval = getInterval();
        var vSymbol = Symbol+","+Interval;


Source = sma(25, close(), sym(vSymbol), 5)  ; 

Length = 20 ;
StdDev = 2 ;
 
bupperBB  = upperBB(Length,StdDev,   Source   );

bmiddleBB = middleBB(Length,StdDev,   Source   );

blowerBB  = lowerBB(Length,StdDev,   Source    ); 
 
tInit  = true ;
}
    

x25x5dma  = Source.getValue(0) ;

xupperBB  = bupperBB.getValue(0) ;
xmiddleBB = bmiddleBB.getValue(0) ;
xlowerBB  = blowerBB.getValue(0) ; 


/*

setBarBgColor(Color.white, 0);

if(   ) {
     setBarBgColor( , 0);
        if( iAlert == true ) {
    Alert.addToList(getSymbol(), close(0) +"  ", Color.blue, Color.black);
        Alert.playSound("ding.wav");
        }
}

if(   ) {
     setBarBgColor( , 0);
        if( iAlert == true ) {
    Alert.addToList(getSymbol(), close(0) +"  ", Color.red, Color.black);
        Alert.playSound("ding.wav");
        }
}


     setBarFgColor( , 0);
     setBarFgColor( , 1);  

*/

return new Array( x25x5dma , xupperBB , xmiddleBB , xlowerBB );

}


function editParameters() {
    askForInput("$TRO_DMABB");
    return;
}