Your example is quite similar to the sunburst partition example, which also updates data with a transition. The difference is that in this example it's the same underlying data with different value accessors. This means that you can't save the previous value in the data (as that will be different), but need to put it somewhere else (e.g. the DOM element).
The updated tween function looks like this:
function arcTweenUpdate(a) {
var i = d3.interpolate({x: this.x0, dx: this.dx0}, a);
return function(t) {
var b = i(t);
this.x0 = b.x;
this.dx0 = b.dx;
return arc(b);
};
}
This requires, as in the original example, to save the original x
and dx
values:
.enter().append("path")
.each(function(d) {
this.x0 = d.x;
this.dx0 = d.dx;
});
Complete example here. This one has a kind of weird transition which is cause by the different order of the data in the layout. You can disable that by calling .sort(null)
, see here.