Specify loop range

[sherdeadlock]

Shape loop all the data. Can it provide an API that specifying a range? ex:

area(data, 5000, 6000);

[mbostock]

Use array.slice?

area(data.slice(5000, 6000));

[sherdeadlock]

It can improve some performance while changing range rapidly.

[mbostock]

I’m skeptical that array.slice is the performance bottleneck here. You could avoid the allocation in array.slice by copying into a pre-existing array. Or use area.defined to render a subset of the array:

area.defined(function(d, i) { return 5000 >= i && i < 6000; })(data);