using an average function in Qualtrics

Question

I'm trying to write a function to compute an average of embedded data. I piped the fields in, parse them (they are numbers with decimals, so I can use parseInt). Then I need to check if any of the values are zero, so I filter it. I then want to average the data points that are left over.

Qualtrics.SurveyEngine.addOnload(function()
{

var a = "${e://Fields/a}"
var b = "${e://Fields/b}"
var c = "${e://Fields/c}"

var a= parseFloat(a)
var b= parseFloat(b)
var c= parseFloat(c)

var  all_values;
var all_values= [a, b, c];

function isnonzero(value) {
    return value != 0;
}   

var filter_it;
var filter_it = all_values.filter(isnonzero);

function avg(filter_it){
var sum = 0;
for (var i = 0; i < filter_it.length; i++) {
sum += parseFloat(arr[i])
}
return average= sum / i;
}

Qualtrics.SurveyEngine.setEmbeddedData("total",average);

I don't think my function is right, or the way I tried to get the info out of the function. Any help would be awesome!

Answer 1

You have a couple of problems here, first, you don't need to re-initialize a variable after it has been defined. Second, you never call your avg() function. And third, you can't use the value of i outside of the for loop. YOu also never define arr in the avg() function. And you don't define average outside the avg function Try the following:

Qualtrics.SurveyEngine.addOnload(function()
{
    var a = "${e://Fields/a}"
    var b = "${e://Fields/b}"
    var c = "${e://Fields/c}"

    a= parseFloat(a)
    b= parseFloat(b)
    c= parseFloat(c)
    var all_values= [a, b, c];
    function isnonzero(value) {
        return value != 0;
    }   
    var filter_it;
    filter_it = all_values.filter(isnonzero);
    function avg(filter_it){
        var sum = 0;
        for (var i = 0; i < filter_it.length; i++) {
            sum += parseFloat(filter_it[i])
        }
        return sum / filter_it.length;
    }
    var average = avg(filter_it);
    Qualtrics.SurveyEngine.setEmbeddedData("total",average);

});