EMA alert

[Richard Yu]

I hv written below EFS to give alert when the EMA is touched. It is supposed to give alert only once per bar. However, it keeps on sending out alerts for the same bar. Any advice? thx

var nEMALength = 20;
var bEMAAlert0 = false;

var EMAAlert0Mode = 0;
var EMAButton0Text = "this EMA";
var EMAButton0Color = Color.grey;
var EMAAlert0Sound = "thisEMAalert.wav";


function preMain()
{
    setPriceStudy(true);    
}

function main()
{   
    dThisEMA = ema(nEMALength);
    
    RichButtons();
    
    if( getBarState() == BARSTATE_ALLBARS ) {
        thisInterval = getInterval();
        thisSymbol = getSymbol();
    }
    
    if ( high()>=dThisEMA && low()<=dThisEMA ) {
        if (EMAAlert0Mode==1 && !bEMAAlert0) {   
            Alert.addToList(thisSymbol, thisInterval+" :EMA is touched", Color.black, Color.purple);
            Alert.playSound(EMAAlert0Sound);
        }
        bEMAAlert0 = true;
    } else
        bEMAAlert0 = false;
        
    return;
    
}


function EMAButton0CallBack(nButtonPressed) {
    if (EMAAlert0Mode == 0){
        EMAAlert0Mode = 1;
        EMAButton0Color = Color.cyan; 
    } else {
        EMAAlert0Mode = 0;
        EMAButton0Color = Color.grey; 
    }
    RichButtons();
    return;
}

function RichButtons(){
   
    drawTextAbsolute(0, 70, EMAButton0Text+"@URL=EFS:EMAButton0CallBack", 
        Color.black, EMAButton0Color, 
        Text.RELATIVETOTOP | Text.RELATIVETOLEFT | Text.LEFT | Text.FRAME | Text.ONTOP | Text.BOLD, null, 10, 
        "EMAButton0");
    return;
} 

[eSignal_JasonK]

Hello Richard,

You are very close. You are properly setting your control flag to true the first time your alert condition is true. The problem is that during the same interval, the first occurence where your alert condition then evaluates back to false, your else statement gets executed and resets your control flag back to false. The next trade that occurs after that where your alert condition evaluates to true again also executes your alert again because the control variable was reset to false.

What you need to do is only reset the control variable back to false at BARSTATE_NEWBAR. That way, your alert will only execute the first time the alert condition evaluates to true for the duration of that bar. Try the modified code below. Also notice that I removed the else statement where you were previously allowing the control variable to get reset during the bar.

function main()
{   
    dThisEMA = ema(nEMALength);
    
    RichButtons();
    
    if( getBarState() == BARSTATE_ALLBARS ) {
        thisInterval = getInterval();
        thisSymbol = getSymbol();
    }
    
    if (getBarState() == BARSTATE_NEWBAR) {
        bEMAAlert0 = false;
    }
    
    if ( high()>=dThisEMA && low()<=dThisEMA ) {
        if (EMAAlert0Mode==1 && !bEMAAlert0) {   
            Alert.addToList(thisSymbol, thisInterval+" :EMA is touched", Color.black, Color.purple);
            Alert.playSound(EMAAlert0Sound);
        }
        bEMAAlert0 = true;
    }
   
    return;
    
} 

[Richard Yu]

I hv below EMAs on a 10min chart for NQ#F with time template of 9:30-16:15.

v0 = ema(20);
v1 = ema(20, inv(60));
v2 = ema(20, inv(240));

However, the system keeps on sending alerts out telling me that the 240min 20-EMA has been touched. Any advice?

[eSignal_JasonK]

Hello Richard,

Without seeing the code you're using it's difficult to provide any guidance. Please post your formula as an attachment and I'll take a look.

[Richard Yu]

pls see the attached file. thx.

[eSignal_JasonK]

Hello Richard,

Thank your for posting your code, which was also nice and tidy. Much appreciated. I think the problem is on line 114.

if (EMAAlert3Mode==1 && MuteAllMode==0 && !bEMAAlert1) { 

bEMAAlert1 should be bEMAAlert3

if (EMAAlert3Mode==1 && MuteAllMode==0 && !bEMAAlert3) { 

[Richard Yu]

thank you. So I hv made a stupid mistake...