v2.0.0
See https://observablehq.com/@d3/d3-array-2-0 for details.
- Add d3.quickselect.
- Add d3.group.
- Add d3.rollup.
- Rewrite d3.median to use quickselect.
- Accept iterables (not just arrays) where relevant.
- Allow more than two iterables for d3.cross.
Note: this release adopts ES2015 language features such as for-of and drops support for older browsers, including IE. If you need to support pre-ES2015 environments, you should stick with d3-array 1.x or use a transpiler.