Learn D3.js

Modifying the structure of the node tree

The methods listed here alter the structure of a DOM tree, either by adding new elements, changing their position, or detaching them from the tree. Since selections are immutable, these methods always return new selections:

Method	Description
append(tagname | function)	If the parameter is a string, it must be a tag name. The method will create a new element and append it as the last child of each element in the selection, returning a new selection with the appended nodes. If the selection is an enter selection (see general update pattern), the nodes are added as siblings following the selected nodes. If the parameter is a function, it must return a DOM element to be appended.
insert( ...