Study On A Study

[paulford]

so I came up with this simple little formula to plot $ADD as a histogram, any way to plot a 20ema of the $ADD on the same?

function preMain()
{
setStudyTitle("ADVDEC");
setCursorLabelName("ADD");
setDefaultBarFgColor(Color.red);
setPlotType(PLOTTYPE_HISTOGRAM);

}
function main()
{
var vA;



vA = getValue("Close",0,1,"$ADD");


return (vA);
}

[eSignal_JasonK]

Hello paulford,

Try the following. I'm using a global array to store the previous 19 values of vA to calculate the moving average, which includes the current bar's vA. At the top of main when our bar state is NEWBAR, update the array before calculating your new value for vA.

addBand(0, PS_SOLID, 1, Color.red, "zero");

function preMain() {
    setStudyTitle("ADVDEC");
    setCursorLabelName("ADD", 0);
    setCursorLabelName("ADD MA", 1);
    setDefaultBarFgColor(Color.red, 0);
    setDefaultBarFgColor(Color.blue, 1);
    setPlotType(PLOTTYPE_HISTOGRAM, 0);
}

var myArray = new Array(19);
var vA = null;

function main() {
    if (getBarState() == BARSTATE_NEWBAR && vA != null) {
        myArray.pop();
        myArray.unshift(vA);
    }
    
    vA = getValue("Close",0,1,"$ADD") * 1;
    if (vA == null)
        return;
    
    var vAma = null;
    if (myArray[18] != null) {
        var dSum = 0;
        for (i = 0; i < 19; ++i) {
            dSum += myArray[i];
        }
        vAma = (dSum + vA)/20;
    }
    return new Array(vA, vAma);
} 

[paulford]

wow that's works great, thank you very much!

is there anyway i can tweak that moving average into an exponential?

[eSignal_JasonK]

Hello paulford,

I thought you might ask for that. Here you go. I set it up so that you can use the "Edit Studies" option to toggle this formula from simple to exponential. For the input parameter, enter EMA or MA.

addBand(0, PS_SOLID, 1, Color.red, "zero");

function preMain() {
    setStudyTitle("ADVDEC");
    setCursorLabelName("ADD", 0);
    setCursorLabelName("ADD MA", 1);
    setDefaultBarFgColor(Color.red, 0);
    setDefaultBarFgColor(Color.blue, 1);
    setPlotType(PLOTTYPE_HISTOGRAM, 0);
}

var dLastMA2 = null;
var dThisMA2 = null;
var bPrimed2 = false;
var dPercent2 = (2.0 / (20 + 1.0));


function ema() {
    var nBarState = getBarState();
    var dValue2;
    var dSum = 0.0;

    if(nBarState == BARSTATE_ALLBARS) {
        // reset!
        dLastMA2 = null;
        dThisMA2 = null;
    }

    if(nBarState == BARSTATE_NEWBAR) {
        dLastMA2 = dThisMA2;
    }
    dThisMA2 = dLastMA2;
    
    if (myArray[18] != null) {
        if (bPrimed2 == false) {
            dValue2 = new Array(19);
            for (i = 0; i < 19; ++i) {
                dValue2[i] = myArray[i];
            }
            dSum = 0;
            for(i = 0; i < 19; i++) {
                dSum += dValue2[i];
            }
            dSum += vA;
            dLastMA2 = dSum / 20;
            dThisMA2 = dLastMA2;
            bPrimed2 = true;
        } else {
            dThisMA2 = (vA - dLastMA2) * dPercent2 + dLastMA2;
        }
    }
    return dThisMA2;
}

var myArray = new Array(19);
var vA = null;

function main(nType) {
    if (nType == null) {
        nType = "EMA";
    } else {
        nType = "MA";
    }
    
    if (getBarState() == BARSTATE_NEWBAR && vA != null) {
        myArray.pop();
        myArray.unshift(vA);
    }
    
    vA = getValue("Close",0,1,"$ADD") * 1;
    if (vA == null)
        return;
    
/*** simple moving average *********/
    if (nType == "MA") {
        var vAma = null;
        if (myArray[18] != null) {
            var dSum = 0;
            for (i = 0; i < 19; ++i) {
                dSum += myArray[i];
            }
            vAma = (dSum + vA)/20;
        }
        return new Array(vA, vAma);
    }
/***********************************/


/*** expontential moving average ***/
    if (nType == "EMA") {
        var vAema = null;
        vAema = ema();
        return new Array(vA, vAema);
    }
/***********************************/
} 

[paulford]

aces again!

thanks alot

[dloomis]

Jason

Do you have an editor to line up all of the { and {'s so nice and neat, or are you just a neat and tidy person by nature?

What is the editor called, btw?

[eSignal_JasonK]

Hi David,

I'm just neat and tidy by nature. I use tabs instead of spaces to begin each line to keep everything lined up nicely.