Function cross

src/plots/geo/zoom.js:456–462

(a, b)

}

function cross(a, b) {
    return [
        a[1] * b[2] - a[2] * b[1],
        a[2] * b[0] - a[0] * b[2],
        a[0] * b[1] - a[1] * b[0]
    ];
}

// Like d3.dispatch, but for custom events abstracting native UI events. These
// events have a target component (such as a brush), a target element (such as