d3/docs/d3-transition.md

d3-transition

A transition is a selection-like interface for animating changes to the DOM. Instead of applying changes instantaneously, transitions smoothly interpolate the DOM from its current state to the desired target state over a given duration.

To apply a transition, select elements, call selection.transition, and then make the desired changes. For example:

d3.select("body")
  .transition()
    .style("background-color", "red");

Transitions support most selection methods (such as transition.attr and transition.style in place of selection.attr and selection.style), but not all methods are supported; for example, you must append elements or bind data before a transition starts. A transition.remove operator is provided for convenient removal of elements when the transition ends.

To compute intermediate state, transitions leverage a variety of built-in interpolators. Colors, numbers, and transforms are automatically detected. Strings with embedded numbers are also detected, as is common with many styles (such as padding or font sizes) and paths. To specify a custom interpolator, use transition.attrTween, transition.styleTween or transition.tween.

See one of:

• Selecting elements
• Modifying elements
• Timing
• Control flow