I wanted to know how much a point on svg moved when the user uses the wheel scroll to zoom in/out at a certain point in the svg.

for ex:

https://bl.ocks.org/mbostock/2206340

In my case, I need to track how much the center of the SVG moved(in both X and Y direction) when user uses d3 zoom scroll wheel to zoom in/out at a particular point considering the scale .