行为

Drag

d3.behavior.zoom - create a zoom behavior.
zoom - apply the zoom behavior to the selected elements.
zoom.scale - the current scale factor.
zoom.translate - the current translate offset.
zoom.scaleExtent - optional limits on the scale factor.
zoom.center - an optional focal point for mousewheel zooming.
zoom.size - the dimensions of the viewport.
zoom.duration - get or set the dblclick transition duration.
zoom.x - an optional scale whose domain is bound to the x extent of the viewport.
zoom.y - an optional scale whose domain is bound to the y extent of the viewport.
zoom.on - listeners for when the scale or translate changes.
zoom.event - dispatch zoom events after setting the scale or translate.