bug in d3.js library, to instantiate a new node of a tree diagram, if you want to redesign a tree you need to instantiate the new object with the childrens attributto non-null.
LucaCorcella/d3Bug
bug in d3.js library, to instantiate a new node of a tree diagram, if you want to redesign a tree you need to instantiate the new object with the childrens attributto non-null.