Cumulative sum, Moving sum

[xoprofittaker]

What is the proper syntax to perform a continuous sum function
that will give you a total back to the begining of the data base.

Also can I perform a task that will give a sum for the prior 30
bars.

If a close - close.1 function returns values of 100, -3 that does
not mean that the value of our indicator dropped 103 points.

It only dropped 3 points and our indicator line should drop to a value of 97 not -3.

Any help would be appreciated.

thanks, John

[eSignal_JasonK]

Re: Cumulative sum, Moving sum

Hello John,

Originally posted by xoprofittaker
What is the proper syntax to perform a continuous sum function
that will give you a total back to the begining of the data base.

The easiest thing to do is use a global variable and add up the data bar-by-bar as the formula is loading. Then add the real time bar's data to the global variable after it closes. The following example accomplishes this for the volume values.

var nSum = 0;

function main() {
    var nVol = volume(-1);
    if (nVol == null) return;
    
    if (getBarState() == BARSTATE_NEWBAR) {
        nSum += nVol;
    }
 
    return nSum;
} 

Also can I perform a task that will give a sum for the prior 30
bars.

Yes, one way to accomplish this is with a for loop.

var nSum = 0;

function main() {
    if (volume(-30) == null) return;
    if (getBarState() == BARSTATE_NEWBAR) {
        nSum = 0;
        for (var i = 1; i <= 30; i++) {
            nSum += volume(-i);
        }
    }
    
    return nSum;
} 

If a close - close.1 function returns values of 100, -3 that does
not mean that the value of our indicator dropped 103 points.

It only dropped 3 points and our indicator line should drop to a value of 97 not -3.

Any help would be appreciated.

thanks, John

Your last question is difficult to answer without seeing your code. The expression, close - close.1, is not valid EFS syntax. In looking at the basic math you've described a value of 100 minus a value of -3 is equal to 103.

debugPrintln(100 - -3); // prints 103

If you want that result to become 97 you would need to take the absolute value of -3 and subtract that from 100. See the abs() method of the Math Object.

debugPrintln(100 - Math.abs(-3)); // prints 97