d3包布局中的访问比例因子

Question

I'm using d3's pack layout with the default radius function. This scales the size of the circles so that everything fits into the container.

How can I access this scale factor?

Answer 1

This code will display scaling factor in node's tooltip:

titles
    .attr("x", function(d) { return d.x; })
    .attr("y", function(d) { return d.y; })
    .text(function(d) {
        return (    "Scale factor  : " + (+d.value)/(d.r*d.r) + "\n" +
                    "Value: "  + d.value + "\n" +
                    "R: "  + d.r); 
    });

as in this test example jsfiddle .

It looks the scaling factor is more or less the same for all leaf nodes in a circle pack, as illustrated in following two pictures:

However, it may vary for all other nodes!