transition.on(typenames[, listener]) Adds or removes a listener to each selected element for the specified event typenames. The typenames is one of the following string event types: start - when the transition starts. end - when the transition ends. interrupt - when the transition is interrupted. See The Life of a Transition for more. Note that these are not native DOM events as implemented by selection.on and selection.dispatch, but transition events! The type may be optionally followe

transition.remove() For each selected element, removes the element when the transition ends, as long as the element has no other active or pending transitions. If the element has other active or pending transitions, does nothing.

transition.select(selector) For each selected element, selects the first descendant element that matches the specified selector string, if any, and returns a transition on the resulting selection. The selector may be specified either as a selector string or a function. If a function, it is evaluated for each selected element, in order, being passed the current datum d and index i, with the this context as the current DOM element. The new transition has the same id, name and timing as this tr

transition.filter(filter) For each selected element, selects only the elements that match the specified filter, and returns a transition on the resulting selection. The filter may be specified either as a selector string or a function. If a function, it is evaluated for each selected element, in order, being passed the current datum d and index i, with the this context as the current DOM element. The new transition has the same id, name and timing as this transition; however, if a transition

transition.merge(other) Returns a new transition merging this transition with the specified other transition, which must have the same id as this transition. The returned transition has the same number of groups, the same parents, the same name and the same id as this transition. Any missing (null) elements in this transition are filled with the corresponding element, if present (not null), from the other transition. This method is equivalent to deriving the selection for this transition via

transition.nodes() Returns an array of all (non-null) elements in this transition. Equivalent to selection.nodes.

transition.node() Returns the first (non-null) element in this transition. If the transition is empty, returns null. Equivalent to selection.node.

transition.each(function) Invokes the specified function for each selected element, passing in the current datum d and index i, with the this context of the current DOM element. This method can be used to invoke arbitrary code for each selected element, and is useful for creating a context to access parent and child data simultaneously. Equivalent to selection.each.

transition.empty() Returns true if this transition contains no (non-null) elements. Equivalent to selection.empty.

transition.delay([value]) For each selected element, sets the transition delay to the specified value in milliseconds. The value may be specified either as a constant or a function. If a function, it is immediately evaluated for each selected element, in order, being passed the current datum d and index i, with the this context as the current DOM element. The function’s return value is then used to set each element’s transition delay. If a delay is not specified, it defaults to zero. If a va