zoom.transform()

zoom.transform(selection, transform)

If selection is a selection, sets the current zoom transform of the selected elements to the specified transform, instantaneously emitting start, zoom and end events. If selection is a transition, defines a “zoom” tween to the specified transform using d3.interpolateZoom, emitting a start event when the transition starts, zoom events for each tick of the transition, and then an end event when the transition ends (or is interrupted). The transform may be specified either as a zoom transform or as a function that returns a zoom transform. If a function, it is invoked for each selected element, being passed the current datum d and index i, with the this context as the current DOM element.

This function is typically not invoked directly, and is instead invoked via selection.call or transition.call. For example, to reset the zoom transform to the identity transform instantaneously:

selection.call(zoom.transform, d3.zoomIdentity);

To smoothly reset the zoom transform to the identity transform over 750 milliseconds:

selection.transition().duration(750).call(zoom.transform, d3.zoomIdentity);

This method requires that you specify the new zoom transform completely, and does not enforce the defined scale extent and translate extent, if any. To derive a new transform from the existing transform, and to enforce the scale and translate extents, see the convenience methods zoom.translateBy, zoom.scaleBy and zoom.scaleTo.