help: newbie coding problem

[richard1000]

Newbie having trouble coding the following:

new value = (previous value)*0.9 + current value of sym("$ADD")*0.1

What am I doing wrong?

function main(nLength) {

    if(nLength == null)
        nLength = 30;
        
    var nSum = new Array;
    nSum = 0;
    
    var vValue = getValue("Close", 0, -nLength, "$ADD");
    if(vValue == null) {
        return;
    }
    
    for(i = 0; i < nLength; i++) {
        nSum[i] = 0.9*nSum[i-1] + 0.1*vValue[i];
    }
         
    return (nSum);    
} 

[ACM]

Re: help: newbie coding problem

richard1000
You may need to describe what you are trying to accomplish as it is not apparent from the context of your script
Alex

Originally posted by richard1000
Newbie having trouble coding the following:

new value = (previous value)*0.9 + current value of sym("$ADD")*0.1

What am I doing wrong?

function main(nLength) {

    if(nLength == null)
        nLength = 30;
        
    var nSum = new Array;
    nSum = 0;
    
    var vValue = getValue("Close", 0, -nLength, "$ADD");
    if(vValue == null) {
        return;
    }
    
    for(i = 0; i < nLength; i++) {
        nSum[i] = 0.9*nSum[i-1] + 0.1*vValue[i];
    }
         
    return (nSum);    
} 

[richard1000]

Hello Alex, maybe the following link will clear things up. link

I'm trying to replicate how he calculates Advance Decline Oscillator(ADO) and display it as an indicator.

[ACM]

richard1000
Enclosed below is a revision of your script

var vValue = null;

function main() {

    if(vValue==null) vValue = close(sym("$ADD"));
     var nSum_1 = ref(-1);

    if(vValue.getValue(0) == null ) {
        return;
    }
   
    var  nSum = 0.9 * nSum_1 + 0.1 * vValue.getValue(0);
         
    return (nSum);    
} 

Note that to retrieve the previous value of the indicator I used the ref() function. For information on this function see this article in the EFS KnowledgeBase. You may also want to see my reply in this post with regards to other methods of retrieving prior values of a custom variable
Also note that rather than calling the external symbol using the legacy getValue() function which syncs it by bar index I used instead the efs2 functionality and called the external symbol using the sym() function which will sync it by date and time
For information and examples on the efs2 close() and sym() functions used in the formula see this and this article in the EFS KnowledgeBase
Alex

Originally posted by richard1000
Hello Alex, maybe the following link will clear things up. link

I'm trying to replicate how he calculates Advance Decline Oscillator(ADO) and display it as an indicator.

[richard1000]

Thanks Alex. I would have never guessed about ref(-1). Got a lot to learn ...

[ACM]

richard1000
You are welcome
Alex

Originally posted by richard1000
Thanks Alex. I would have never guessed about ref(-1). Got a lot to learn ...