The vector.dot function - it's simple right!?

vector.dot.js

var vector = {
    make: function (x, y, z) {
        if (x instanceof Array) {
            return [x[0], x[1], x[2]];
        } else {
            return [x, y, z];
        }
    },
    dot: function (v, w) {
        return (v[0] * w[0] + v[1] * w[1] + v[2] * w[2]);
    },
    // ... more vector functions
};