d3 circles on map projection

d3-circle-map-sample.js

d3.json("data/earthquakes.json", function(r) {
    points.selectAll("circle")
        .data(r.features)
        .enter().append("svg:circle")
        .attr("r", 10)
        .attr("cx", function(d){return map(d.geometry.coordinates)[0];})
        .attr("cy", function(d){return map(d.geometry.coordinates)[1];})
});