Qualtrics: Sum a Single Matrix Column. The last row in the Matrix question is a Total. In this example, the third input column (c6) is the one that is totaled and must add to 100. The totals for the first two input columns (c4 and c5) are hidden. The total is a readonly field so the respondent can't change it. The only other thing to do is add a…

sumSingleMatrixColumn.js

Qualtrics.SurveyEngine.addOnload(function() {
	var q = jQuery("#"+this.questionId);
	q.find('td.c4:last input').hide();
	q.find('td.c5:last input').hide();
	var totalInput = q.find('td.c6:last input');
	totalInput.prop("readonly", true);
	totalInput.css("font-weight", "bold");
	var sumInputs = q.find('td.c6:not(:last) input');
	sumInputs.on("keyup", function(event) {
		sumCol();
	});	
	sumCol();	

	function sumCol() {
		var total = 0;
		sumInputs.each(function(index) {
			var inputValue = parseInt(this.value);
			if(isNaN(inputValue)) inputValue = 0;
			this.value = inputValue;
			total = total + inputValue;
		});
		totalInput.val(total);
		if(total == 100) totalInput.css("color", "");
		else totalInput.css("color", "red");
	}	
});

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