value/values on rollup function about d3-collection

[mbostock]

Yes, this is the expected behavior. Per the README:

The return value of the rollup function will replace the array of leaf values in either the associative array returned by nest.map or nest.object; for nest.entries, it replaces the leaf entry.values with entry.value.

You can try using array.map if you want to change the structure of the returned object. If you have further questions, also consider using Stack Overflow or the d3-js Google group to ask for help. Thank you!

[Niekes]

Ok, thanks !