Show data on mouseover of circle

Question

I have a set of data that I am plotting in a scatter. When I mouseover one of the circles I would like it to popup with data (like x, y values, maybe more). Here is what I

Answer 1

I assume that what you want is a tooltip. The easiest way to do this is to append an svg:title element to each circle, as the browser will take care of showing the tooltip and you don't need the mousehandler. The code would be something like

vis.selectAll("circle")
   .data(datafiltered).enter().append("svg:circle")
   ...
   .append("svg:title")
   .text(function(d) { return d.x; });

If you want fancier tooltips, you could use tipsy for example. See here for an example.