Javascript to Calculate the Average of a column

Question

I have a column of fields in my PDF that I am trying to calculate the average for.
My problem is that there are 7 fields, but all 7 may not be filled in so I think I need some kind of "if" statement that would only count the number of fields that have values.  Then somehow work that into the rest of my calculation...
This is what I have so far...
(function () {
    // Get all of the field values, as numbers
    var v1 = +getField("column.0").value;
    var v2 = +getField("column.1").value;
    var v3 = +getField("column.2").value;
    var v4 = +getField("column.3").value;
    var v5 = +getField("column.4").value;
    var v6 = +getField("column.5").value;
    var v7 = +getField("column.6").value;
    var v8 = +getField("column.7").value;
    // Calculate the result and set this field value
    event.value = (v1 + v2 + v3 + v4 + v5 + v6 + v7) / the number of fields that were filled in;
I'm pretty new to javascript. Any help would be greatly appreciated! THANKS

Answer 1

First, I woul write this function withou field references to make it more universial, and then I would make it a document level funcion so it could be used more than once in a PDF and easily brought into another PDF.
function Avg() {
// computer average of non-empty passed field names
var sum = 0; // sum of fields
var count = 0; // counter for non-blank fields
for(i = 0; i < arguments.length; i++) {
var iField = arguments[i]; // get the i element from passed arguments
var fField = this.getField(arguments[i]).value;
if(!(isNaN(fField)) ) {
// field is a number
if(fField.toString() != '') {
// field is not null or blank
sum += Number(fField); // add to sum
count++; // increment count
} // end not blank
} // end number
} // end loop through arguments
if(count != 0) {
// compute average if there is one or more items to average
return sum / count; // return average
} else {
return '';
} // end no average computed
} // end Avg function
Your custom calculation script then becomes:
event.value = Avg('column.0', 'column.1', 'column.2', 'column.3', 'column.4', 'column.5', 'column.6', 'column.7');