Try these:
```
    function readCoordinate(element) {
        var digits = element.textContent.trim().split(/[\s,\n]+/g);
        Cartographic.fromDegrees(digits[0], digits[1], digits[2], scratch);
        return Ellipsoid.WGS84.cartographicToCartesian(scratch);
    }

    function readCoordinates(element) {
        var digits = element.textContent.trim().split(/[\s,\n]+/g);
        var numberOfCoordinates = digits.length / 3;
        var result = new Array(numberOfCoordinates);
        var resultIndex = 0;
        for ( var i = 0; i < digits.length; i += 3) {
            Cartographic.fromDegrees(parseFloat(digits[i]), parseFloat(digits[i]), parseFloat(digits[i]), scratch);
            result[resultIndex++] = Ellipsoid.WGS84.cartographicToCartesian(scratch);
            resultIndex++;
        }
        return result;
    }
```

They take a coordinates element and the first one returns a single Cartesian, the second one returns an array.