chart = {
const svg = d3.create("svg")
.attr("viewBox", [0, 0, width, height]);
svg.append("g")
.call(xAxis);
svg.append("g")
.call(yAxis);
svg.append("g")
.selectAll("circle")
.data(simulation_data)
.join("circle")
.transition()
.delay(function(d,i){return(i*2)})
.duration(200)
.attr("cx", d => x(d.X))
.attr("cy", d => y(d.Y))
.attr("r", 6)
.attr("fill", d => colorScale(d["Training Loss"]));
return svg.node();
}