JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://documentcloud.github.com/underscore/underscore.js"></script>

JavaScript

function createOutput() {
    return _.reduce(arguments, function(memo, arr) {
        return _.map(memo, function(val, index) {
            return {
                x: val.x,
                y: val.y + arr[index].y
            };
        });
    }, _.map(_.range(arguments[0].length), function(val) {
        return {
            x: val + 1,
            y: 0
        };
    }));
}

console.log(createOutput( 
    [{x: 1, y: 2},{x: 2, y: 6},{x: 3, y: 2}],
    [{x: 1, y: 5},{x: 2, y: 3},{x: 3, y: 6}]
));