That's a neat article, with a number of good examples. In the sorting example, I don't think you need either of your `each`s. Almost every D3 method operates

That's a neat article, with a number of good examples. In the sorting example, I don't think you need either of your `each`s. Almost every D3 method operates in bulk. So this example: circles.each(function (d, i) { d3.select(this) .transition() .delay(i*250) .each(animateGrowingCircle(10, 20)); }); could be simply: circles.transition() .delay(function(d, i) { return i*250; }) .call(animateGrowingCircle(10, 20));