in MotionMark/resources/debug-runner/graph.js [463:483]
function addData(name, data, yCoordinateCallback, pointRadius, omitLine) {
var svgGroup = svg.append("g").attr("id", name);
if (!omitLine) {
svgGroup.append("path")
.datum(data)
.attr("d", d3.svg.line()
.x(function(d) { return x(d.time); })
.y(yCoordinateCallback));
}
svgGroup.selectAll("circle")
.data(data)
.enter()
.append("circle")
.attr("cx", function(d) { return x(d.time); })
.attr("cy", yCoordinateCallback)
.attr("r", pointRadius);
cursorGroup.append("circle")
.attr("class", name)
.attr("r", pointRadius + 2);
}