带有d3.js的数据聚合/列表

Question

我是一个新的d3.js用户，我很难进行基本的数据转换。

我想从这种格式转移......

[
  ["enduser-type","supplier","A","Architecture re"],
  ["enduser-type","customer","A","Architecture re"],
  ["enduser-type","consumer","A","Architecture re"],
  ["enduser-type","supplier","B","System Co"],
  ["enduser-type","customer","B","System Co"],
  ["enduser-type","consumer","B","System Co"]
]

......对这一个......

[
  ["enduser-type",["supplier", "customer", "consumer"],"A","Architecture re"],
  ["enduser-type",["supplier", "customer", "consumer"],"B","System Co"]
]

如何执行此转换？

感谢您的帮助