{
const brush = vl.selectInterval()
.encodings('x');
const years = vl.markBar({width: 4})
.data(data)
.params(brush)
.encode(
vl.x().fieldQ('age_difference').title('Age Difference'),
vl.y().count().title(null)
)
.width(600)
.height(50);
const age = vl.markCircle()
.data(data)
.encode(
vl.x().fieldQ('actor_2_age'),
vl.y().fieldQ('actor_1_age'),
vl.size().fieldQ('age_difference'),
vl.color().count().fieldN('director'),
vl.tooltip().fieldN('movie_name'),
vl.opacity().if(brush, vl.value(0.75)).value(0.05)
)
.width(600)
.height(400);
return vl.vconcat(years, age).spacing(5).render();
}