{
const svg = d3.create("svg").attr("width", 300).attr("height", 300);
svg.selectAll("circle")
.data(d3.range(penguinCols.bill_length.length).map(ix => [penguinCols, ix]))
.join(enter => {
enter.append("circle")
.attr("r", 2)
.attr("fill", "black")
.attr("cx", ([data, ix]) => xScale(data.bill_length[ix]))
.attr("cy", ([data, ix]) => yScale(data.bill_depth[ix]))
});
return svg.node();
}